81537746120531 has 2 divisors, whose sum is σ = 81537746120532. Its totient is φ = 81537746120530.

The previous prime is 81537746120459. The next prime is 81537746120591. The reversal of 81537746120531 is 13502164773518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81537746120531 - 2²² = 81537741926227 is a prime.

It is a super-2 number, since 2×81537746120531² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81537746120591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40768873060265 + 40768873060266.

It is an arithmetic number, because the mean of its divisors is an integer number (40768873060266).

Almost surely, 2^{81537746120531} is an apocalyptic number.

81537746120531 is a deficient number, since it is larger than the sum of its proper divisors (1).

81537746120531 is an equidigital number, since it uses as much as digits as its factorization.

81537746120531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4233600, while the sum is 53.

The spelling of 81537746120531 in words is "eighty-one trillion, five hundred thirty-seven billion, seven hundred forty-six million, one hundred twenty thousand, five hundred thirty-one".