1661358960 has 240 divisors, whose sum is σ = 5813065440. Its totient is φ = 424704000.

The previous prime is 1661358953. The next prime is 1661358967. The reversal of 1661358960 is 698531661.

1661358960 is a `hidden beast` number, since 1 + 6 + 6 + 1 + 3 + 589 + 60 = 666.

It is an interprime number because it is at equal distance from previous prime (1661358953) and next prime (1661358967).

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×1661358960² = 5520227187944563200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661358967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5240722 + ... + 5241038.

It is an arithmetic number, because the mean of its divisors is an integer number (24221106).

Almost surely, 2^1661358960 is an apocalyptic number.

1661358960 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661358960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2906532720).

1661358960 is an abundant number, since it is smaller than the sum of its proper divisors (4151706480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661358960 is a wasteful number, since it uses less digits than its factorization.

1661358960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 1661358960 is about 40759.7713438140. The cubic root of 1661358960 is about 1184.3711666554.

The spelling of 1661358960 in words is "one billion, six hundred sixty-one million, three hundred fifty-eight thousand, nine hundred sixty".