81598894631 has 2 divisors, whose sum is σ = 81598894632. Its totient is φ = 81598894630.

The previous prime is 81598894607. The next prime is 81598894633. The reversal of 81598894631 is 13649889518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81598894631 - 2⁶ = 81598894567 is a prime.

It is a super-2 number, since 2×81598894631² (a number of 23 digits) contains 22 as substring.

Together with 81598894633, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81598894633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40799447315 + 40799447316.

It is an arithmetic number, because the mean of its divisors is an integer number (40799447316).

Almost surely, 2^81598894631 is an apocalyptic number.

81598894631 is a deficient number, since it is larger than the sum of its proper divisors (1).

81598894631 is an equidigital number, since it uses as much as digits as its factorization.

81598894631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14929920, while the sum is 62.

The spelling of 81598894631 in words is "eighty-one billion, five hundred ninety-eight million, eight hundred ninety-four thousand, six hundred thirty-one".