81071616631 has 8 divisors (see below), whose sum is σ = 84609798624. Its totient is φ = 77534545440.

The previous prime is 81071616607. The next prime is 81071616641. The reversal of 81071616631 is 13661617018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81071616631 - 2⁷ = 81071616503 is a prime.

It is a super-2 number, since 2×81071616631² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81071616641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126796 + ... + 422161.

It is an arithmetic number, because the mean of its divisors is an integer number (10576224828).

Almost surely, 2^81071616631 is an apocalyptic number.

81071616631 is a deficient number, since it is larger than the sum of its proper divisors (3538181993).

81071616631 is a wasteful number, since it uses less digits than its factorization.

81071616631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555401.

The product of its (nonzero) digits is 36288, while the sum is 40.

The spelling of 81071616631 in words is "eighty-one billion, seventy-one million, six hundred sixteen thousand, six hundred thirty-one".