81717505074 has 32 divisors (see below), whose sum is σ = 181627951680. Its totient is φ = 27234144000.

The previous prime is 81717505073. The next prime is 81717505097. The reversal of 81717505074 is 47050571718.

81717505074 is a `hidden beast` number, since 8 + 1 + 71 + 7 + 505 + 0 + 74 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81717505073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 161874 + ... + 435474.

It is an arithmetic number, because the mean of its divisors is an integer number (5675873490).

Almost surely, 2^81717505074 is an apocalyptic number.

81717505074 is an abundant number, since it is smaller than the sum of its proper divisors (99910446606).

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

81717505074 is a wasteful number, since it uses less digits than its factorization.

81717505074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279143 (or 279137 counting only the distinct ones).

The product of its (nonzero) digits is 274400, while the sum is 45.

The spelling of 81717505074 in words is "eighty-one billion, seven hundred seventeen million, five hundred five thousand, seventy-four".