56806991 has 2 divisors, whose sum is σ = 56806992. Its totient is φ = 56806990.

The previous prime is 56806961. The next prime is 56806993. The reversal of 56806991 is 19960865.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56806991 is a prime.

Together with 56806993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56806993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28403495 + 28403496.

It is an arithmetic number, because the mean of its divisors is an integer number (28403496).

Almost surely, 2^56806991 is an apocalyptic number.

56806991 is a deficient number, since it is larger than the sum of its proper divisors (1).

56806991 is an equidigital number, since it uses as much as digits as its factorization.

56806991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 56806991 is about 7537.0412629891. The cubic root of 56806991 is about 384.4152386631.

The spelling of 56806991 in words is "fifty-six million, eight hundred six thousand, nine hundred ninety-one".