81976401 has 16 divisors (see below), whose sum is σ = 130789120. Its totient is φ = 50446800.

The previous prime is 81976379. The next prime is 81976441. The reversal of 81976401 is 10467918.

81976401 is a `hidden beast` number, since 8 + 1 + 9 + 7 + 640 + 1 = 666.

It is not a de Polignac number, because 81976401 - 2¹¹ = 81974353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81976441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116425 + ... + 117126.

It is an arithmetic number, because the mean of its divisors is an integer number (8174320).

Almost surely, 2^81976401 is an apocalyptic number.

It is an amenable number.

81976401 is a deficient number, since it is larger than the sum of its proper divisors (48812719).

81976401 is a wasteful number, since it uses less digits than its factorization.

81976401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233573 (or 233567 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 81976401 is about 9054.0820075809. The cubic root of 81976401 is about 434.4064675787.

The spelling of 81976401 in words is "eighty-one million, nine hundred seventy-six thousand, four hundred one".