56812981 has 2 divisors, whose sum is σ = 56812982. Its totient is φ = 56812980.

The previous prime is 56812969. The next prime is 56812991. The reversal of 56812981 is 18921865.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46991025 + 9821956 = 6855^2 + 3134^2 .

It is a cyclic number.

It is not a de Polignac number, because 56812981 - 2⁵ = 56812949 is a prime.

It is a super-2 number, since 2×56812981² = 6455429620212722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56812901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28406490 + 28406491.

It is an arithmetic number, because the mean of its divisors is an integer number (28406491).

Almost surely, 2^56812981 is an apocalyptic number.

It is an amenable number.

56812981 is a deficient number, since it is larger than the sum of its proper divisors (1).

56812981 is an equidigital number, since it uses as much as digits as its factorization.

56812981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 40.

The square root of 56812981 is about 7537.4386232990. The cubic root of 56812981 is about 384.4287497135.

The spelling of 56812981 in words is "fifty-six million, eight hundred twelve thousand, nine hundred eighty-one".