61581164038992 has 280 divisors, whose sum is σ = 193365367965000. Its totient is φ = 18877599120384.

The previous prime is 61581164038939. The next prime is 61581164039023. The reversal of 61581164038992 is 29983046118516.

61581164038992 is a `hidden beast` number, since 6 + 1 + 5 + 8 + 1 + 164 + 0 + 389 + 92 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1178796604176 + 60402367434816 = 1085724^2 + 7771896^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 40034134 + ... + 41543882.

It is an arithmetic number, because the mean of its divisors is an integer number (690590599875).

Almost surely, 2^{61581164038992} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61581164038992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96682683982500).

61581164038992 is an abundant number, since it is smaller than the sum of its proper divisors (131784203926008).

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

61581164038992 is a wasteful number, since it uses less digits than its factorization.

61581164038992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1510057 (or 1510036 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 63.

The spelling of 61581164038992 in words is "sixty-one trillion, five hundred eighty-one billion, one hundred sixty-four million, thirty-eight thousand, nine hundred ninety-two".