20976831 has 24 divisors (see below), whose sum is σ = 31590000. Its totient is φ = 13396992.

The previous prime is 20976821. The next prime is 20976833. The reversal of 20976831 is 13867902.

It is not a de Polignac number, because 20976831 - 2²² = 16782527 is a prime.

It is a super-2 number, since 2×20976831² = 880054877605122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20976833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46495 + ... + 46943.

It is an arithmetic number, because the mean of its divisors is an integer number (1316250).

Almost surely, 2^20976831 is an apocalyptic number.

20976831 is a deficient number, since it is larger than the sum of its proper divisors (10613169).

20976831 is a wasteful number, since it uses less digits than its factorization.

20976831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20976831 is about 4580.0470521601. The cubic root of 20976831 is about 275.7909175801.

The spelling of 20976831 in words is "twenty million, nine hundred seventy-six thousand, eight hundred thirty-one".