81593122057 has 8 divisors (see below), whose sum is σ = 85999258440. Its totient is φ = 77293157760.

The previous prime is 81593122049. The next prime is 81593122067. The reversal of 81593122057 is 75022139518.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14625516096 + 66967605961 = 120936^2 + 258781^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81593122057 - 2³ = 81593122049 is a prime.

It is a super-2 number, since 2×81593122057² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81593122007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26541444 + ... + 26544517.

It is an arithmetic number, because the mean of its divisors is an integer number (10749907305).

Almost surely, 2^81593122057 is an apocalyptic number.

It is an amenable number.

81593122057 is a deficient number, since it is larger than the sum of its proper divisors (4406136383).

81593122057 is a wasteful number, since it uses less digits than its factorization.

81593122057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53086043.

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 81593122057 in words is "eighty-one billion, five hundred ninety-three million, one hundred twenty-two thousand, fifty-seven".