81557372854331 has 32 divisors (see below), whose sum is σ = 101472196939776. Its totient is φ = 64594569600000.

The previous prime is 81557372854327. The next prime is 81557372854339. The reversal of 81557372854331 is 13345827375518.

It is not a de Polignac number, because 81557372854331 - 2² = 81557372854327 is a prime.

It is a super-2 number, since 2×81557372854331² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81557372854339) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 305712170 + ... + 305978831.

It is an arithmetic number, because the mean of its divisors is an integer number (3171006154368).

Almost surely, 2^{81557372854331} is an apocalyptic number.

81557372854331 is a deficient number, since it is larger than the sum of its proper divisors (19914824085445).

81557372854331 is a wasteful number, since it uses less digits than its factorization.

81557372854331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611691083.

The product of its digits is 84672000, while the sum is 62.

The spelling of 81557372854331 in words is "eighty-one trillion, five hundred fifty-seven billion, three hundred seventy-two million, eight hundred fifty-four thousand, three hundred thirty-one".