81196631 has 2 divisors, whose sum is σ = 81196632. Its totient is φ = 81196630.

The previous prime is 81196571. The next prime is 81196637. The reversal of 81196631 is 13669118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81196631 - 2¹⁸ = 80934487 is a prime.

It is a super-2 number, since 2×81196631² = 13185785771500322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81196591 and 81196600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81196637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40598315 + 40598316.

It is an arithmetic number, because the mean of its divisors is an integer number (40598316).

Almost surely, 2^81196631 is an apocalyptic number.

81196631 is a deficient number, since it is larger than the sum of its proper divisors (1).

81196631 is an equidigital number, since it uses as much as digits as its factorization.

81196631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 81196631 is about 9010.9173228923. The cubic root of 81196631 is about 433.0247004846.

The spelling of 81196631 in words is "eighty-one million, one hundred ninety-six thousand, six hundred thirty-one".