81696051 has 12 divisors (see below), whose sum is σ = 118168128. Its totient is φ = 54388944.

The previous prime is 81696047. The next prime is 81696053. The reversal of 81696051 is 15069618.

It is not a de Polignac number, because 81696051 - 2² = 81696047 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81695997 and 81696015.

It is not an unprimeable number, because it can be changed into a prime (81696053) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1086 + ... + 12828.

It is an arithmetic number, because the mean of its divisors is an integer number (9847344).

Almost surely, 2^81696051 is an apocalyptic number.

81696051 is a deficient number, since it is larger than the sum of its proper divisors (36472077).

81696051 is a wasteful number, since it uses less digits than its factorization.

81696051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12522 (or 12519 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 81696051 is about 9038.5867811290. The cubic root of 81696051 is about 433.9106950257.

The spelling of 81696051 in words is "eighty-one million, six hundred ninety-six thousand, fifty-one".