656740949 has 2 divisors, whose sum is σ = 656740950. Its totient is φ = 656740948.

The previous prime is 656740937. The next prime is 656740969. The reversal of 656740949 is 949047656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 554367025 + 102373924 = 23545^2 + 10118^2 .

It is a cyclic number.

It is not a de Polignac number, because 656740949 - 2²⁴ = 639963733 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 656740897 and 656740906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656740969) 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, 328370474 + 328370475.

It is an arithmetic number, because the mean of its divisors is an integer number (328370475).

Almost surely, 2^656740949 is an apocalyptic number.

It is an amenable number.

656740949 is a deficient number, since it is larger than the sum of its proper divisors (1).

656740949 is an equidigital number, since it uses as much as digits as its factorization.

656740949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The square root of 656740949 is about 25626.9574666990. The cubic root of 656740949 is about 869.2233121953.

The spelling of 656740949 in words is "six hundred fifty-six million, seven hundred forty thousand, nine hundred forty-nine".