1661736960 has 576 divisors, whose sum is σ = 6618175200. Its totient is φ = 382205952.

The previous prime is 1661736919. The next prime is 1661736971. The reversal of 1661736960 is 696371661.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×1661736960² = 5522739448460083200, which contains 22 as substring.

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

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22763484 + ... + 22763556.

Almost surely, 2^1661736960 is an apocalyptic number.

1661736960 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 1661736960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3309087600).

1661736960 is an abundant number, since it is smaller than the sum of its proper divisors (4956438240).

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

1661736960 is a wasteful number, since it uses less digits than its factorization.

1661736960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 1661736960 is about 40764.4080050232. The cubic root of 1661736960 is about 1184.4609843614.

The spelling of 1661736960 in words is "one billion, six hundred sixty-one million, seven hundred thirty-six thousand, nine hundred sixty".