656543401 has 2 divisors, whose sum is σ = 656543402. Its totient is φ = 656543400.

The previous prime is 656543357. The next prime is 656543411. The reversal of 656543401 is 104345656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 358117776 + 298425625 = 18924^2 + 17275^2 .

It is a cyclic number.

It is not a de Polignac number, because 656543401 - 2¹⁵ = 656510633 is a prime.

It is not a weakly prime, because it can be changed into another prime (656543411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328271700 + 328271701.

It is an arithmetic number, because the mean of its divisors is an integer number (328271701).

Almost surely, 2^656543401 is an apocalyptic number.

It is an amenable number.

656543401 is a deficient number, since it is larger than the sum of its proper divisors (1).

656543401 is an equidigital number, since it uses as much as digits as its factorization.

656543401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 34.

The square root of 656543401 is about 25623.1028761155. The cubic root of 656543401 is about 869.1361491887.

The spelling of 656543401 in words is "six hundred fifty-six million, five hundred forty-three thousand, four hundred one".