56720987 has 2 divisors, whose sum is σ = 56720988. Its totient is φ = 56720986.

The previous prime is 56720969. The next prime is 56721001. The reversal of 56720987 is 78902765.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 56720987 - 2¹⁰ = 56719963 is a prime.

It is not a weakly prime, because it can be changed into another prime (56720887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28360493 + 28360494.

It is an arithmetic number, because the mean of its divisors is an integer number (28360494).

Almost surely, 2^56720987 is an apocalyptic number.

56720987 is a deficient number, since it is larger than the sum of its proper divisors (1).

56720987 is an equidigital number, since it uses as much as digits as its factorization.

56720987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 211680, while the sum is 44.

The square root of 56720987 is about 7531.3336800330. Note that the first 3 decimals coincide. The cubic root of 56720987 is about 384.2211431465.

The spelling of 56720987 in words is "fifty-six million, seven hundred twenty thousand, nine hundred eighty-seven".