81130375608 has 32 divisors (see below), whose sum is σ = 206263670400. Its totient is φ = 26585094368.

The previous prime is 81130375597. The next prime is 81130375661. The reversal of 81130375608 is 80657303118.

It is a super-2 number, since 2×81130375608² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81130375608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28646316 + ... + 28649147.

It is an arithmetic number, because the mean of its divisors is an integer number (6445739700).

Almost surely, 2^81130375608 is an apocalyptic number.

It is an amenable number.

81130375608 is an abundant number, since it is smaller than the sum of its proper divisors (125133294792).

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

81130375608 is a wasteful number, since it uses less digits than its factorization.

81130375608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57295531 (or 57295527 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 81130375608 in words is "eighty-one billion, one hundred thirty million, three hundred seventy-five thousand, six hundred eight".