61660329995520 has 360 divisors, whose sum is σ = 232244151179040. Its totient is φ = 15577346027520.

The previous prime is 61660329995483. The next prime is 61660329995521. The reversal of 61660329995520 is 2559992306616.

61660329995520 is a `hidden beast` number, since 6 + 16 + 6 + 0 + 3 + 2 + 9 + 9 + 95 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61660329995521) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 13680546 + ... + 17620385.

It is an arithmetic number, because the mean of its divisors is an integer number (645122642164).

Almost surely, 2^{61660329995520} is an apocalyptic number.

61660329995520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61660329995520 is an abundant number, since it is smaller than the sum of its proper divisors (170583821183520).

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

61660329995520 is a wasteful number, since it uses less digits than its factorization.

61660329995520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31300983 (or 31300960 counting only the distinct ones).

The product of its (nonzero) digits is 47239200, while the sum is 63.

The spelling of 61660329995520 in words is "sixty-one trillion, six hundred sixty billion, three hundred twenty-nine million, nine hundred ninety-five thousand, five hundred twenty".