81976851 has 24 divisors (see below), whose sum is σ = 129729600. Its totient is φ = 49470000.

The previous prime is 81976819. The next prime is 81976861. The reversal of 81976851 is 15867918.

It is not a de Polignac number, because 81976851 - 2⁵ = 81976819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81976797 and 81976806.

It is not an unprimeable number, because it can be changed into a prime (81976861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23200 + ... + 26498.

It is an arithmetic number, because the mean of its divisors is an integer number (5405400).

Almost surely, 2^81976851 is an apocalyptic number.

81976851 is a deficient number, since it is larger than the sum of its proper divisors (47752749).

81976851 is a wasteful number, since it uses less digits than its factorization.

81976851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3567 (or 3564 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 81976851 is about 9054.1068582163. The cubic root of 81976851 is about 434.4072624520.

The spelling of 81976851 in words is "eighty-one million, nine hundred seventy-six thousand, eight hundred fifty-one".