56705921 has 2 divisors, whose sum is σ = 56705922. Its totient is φ = 56705920.

The previous prime is 56705917. The next prime is 56705939. The reversal of 56705921 is 12950765.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52765696 + 3940225 = 7264^2 + 1985^2 .

It is a cyclic number.

It is not a de Polignac number, because 56705921 - 2² = 56705917 is a prime.

It is a super-2 number, since 2×56705921² = 6431122952916482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (56705951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28352960 + 28352961.

It is an arithmetic number, because the mean of its divisors is an integer number (28352961).

Almost surely, 2^56705921 is an apocalyptic number.

It is an amenable number.

56705921 is a deficient number, since it is larger than the sum of its proper divisors (1).

56705921 is an equidigital number, since it uses as much as digits as its factorization.

56705921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 35.

The square root of 56705921 is about 7530.3333923539. Note that the first 4 decimals coincide. The cubic root of 56705921 is about 384.1871217102.

The spelling of 56705921 in words is "fifty-six million, seven hundred five thousand, nine hundred twenty-one".