957721 has 2 divisors, whose sum is σ = 957722. Its totient is φ = 957720.

The previous prime is 957709. The next prime is 957731. The reversal of 957721 is 127759.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 541696 + 416025 = 736^2 + 645^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-957721 is a prime.

It is not a weakly prime, because it can be changed into another prime (957701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 478860 + 478861.

It is an arithmetic number, because the mean of its divisors is an integer number (478861).

2⁹⁵⁷⁷²¹ is an apocalyptic number.

It is an amenable number.

957721 is a deficient number, since it is larger than the sum of its proper divisors (1).

957721 is an equidigital number, since it uses as much as digits as its factorization.

957721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4410, while the sum is 31.

The square root of 957721 is about 978.6322087485. The cubic root of 957721 is about 98.5703586565.

The spelling of 957721 in words is "nine hundred fifty-seven thousand, seven hundred twenty-one".