81607543231 has 2 divisors, whose sum is σ = 81607543232. Its totient is φ = 81607543230.

The previous prime is 81607543217. The next prime is 81607543253. The reversal of 81607543231 is 13234570618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81607543231 - 2⁹ = 81607542719 is a prime.

It is a super-2 number, since 2×81607543231² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81607543271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40803771615 + 40803771616.

It is an arithmetic number, because the mean of its divisors is an integer number (40803771616).

Almost surely, 2^81607543231 is an apocalyptic number.

81607543231 is a deficient number, since it is larger than the sum of its proper divisors (1).

81607543231 is an equidigital number, since it uses as much as digits as its factorization.

81607543231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 81607543231 in words is "eighty-one billion, six hundred seven million, five hundred forty-three thousand, two hundred thirty-one".