656917813 has 2 divisors, whose sum is σ = 656917814. Its totient is φ = 656917812.

The previous prime is 656917771. The next prime is 656917819. The reversal of 656917813 is 318719656.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 440916004 + 216001809 = 20998^2 + 14697^2 .

It is a cyclic number.

It is not a de Polignac number, because 656917813 - 2¹³ = 656909621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656917819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328458906 + 328458907.

It is an arithmetic number, because the mean of its divisors is an integer number (328458907).

Almost surely, 2^656917813 is an apocalyptic number.

It is an amenable number.

656917813 is a deficient number, since it is larger than the sum of its proper divisors (1).

656917813 is an equidigital number, since it uses as much as digits as its factorization.

656917813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 46.

The square root of 656917813 is about 25630.4079756839. The cubic root of 656917813 is about 869.3013340869.

The spelling of 656917813 in words is "six hundred fifty-six million, nine hundred seventeen thousand, eight hundred thirteen".