656401673 has 2 divisors, whose sum is σ = 656401674. Its totient is φ = 656401672.

The previous prime is 656401667. The next prime is 656401687. The reversal of 656401673 is 376104656.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 492484864 + 163916809 = 22192^2 + 12803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656401673 is a prime.

It is not a weakly prime, because it can be changed into another prime (656401073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328200836 + 328200837.

It is an arithmetic number, because the mean of its divisors is an integer number (328200837).

Almost surely, 2^656401673 is an apocalyptic number.

It is an amenable number.

656401673 is a deficient number, since it is larger than the sum of its proper divisors (1).

656401673 is an equidigital number, since it uses as much as digits as its factorization.

656401673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 656401673 is about 25620.3370977042. The cubic root of 656401673 is about 869.0736045584.

The spelling of 656401673 in words is "six hundred fifty-six million, four hundred one thousand, six hundred seventy-three".