1661061120 has 192 divisors, whose sum is σ = 5366088000. Its totient is φ = 438632448.

The previous prime is 1661061107. The next prime is 1661061133. The reversal of 1661061120 is 211601661.

It is an interprime number because it is at equal distance from previous prime (1661061107) and next prime (1661061133).

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4269886 + ... + 4270274.

It is an arithmetic number, because the mean of its divisors is an integer number (27948375).

Almost surely, 2^1661061120 is an apocalyptic number.

1661061120 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 1661061120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2683044000).

1661061120 is an abundant number, since it is smaller than the sum of its proper divisors (3705026880).

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

1661061120 is a wasteful number, since it uses less digits than its factorization.

1661061120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 538 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1661061120 is about 40756.1175776104. The cubic root of 1661061120 is about 1184.3003864089.

Adding to 1661061120 its reverse (211601661), we get a palindrome (1872662781).

The spelling of 1661061120 in words is "one billion, six hundred sixty-one million, sixty-one thousand, one hundred twenty".