56287991 has 2 divisors, whose sum is σ = 56287992. Its totient is φ = 56287990.

The previous prime is 56287967. The next prime is 56287997. The reversal of 56287991 is 19978265.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 56287991 - 2¹⁸ = 56025847 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56287997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28143995 + 28143996.

It is an arithmetic number, because the mean of its divisors is an integer number (28143996).

Almost surely, 2^56287991 is an apocalyptic number.

56287991 is a deficient number, since it is larger than the sum of its proper divisors (1).

56287991 is an equidigital number, since it uses as much as digits as its factorization.

56287991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 47.

The square root of 56287991 is about 7502.5323058285. The cubic root of 56287991 is about 383.2409571149.

The spelling of 56287991 in words is "fifty-six million, two hundred eighty-seven thousand, nine hundred ninety-one".