656680201909 has 2 divisors, whose sum is σ = 656680201910. Its totient is φ = 656680201908.

The previous prime is 656680201799. The next prime is 656680201927. The reversal of 656680201909 is 909102086656.

656680201909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490035000625 + 166645201284 = 700025^2 + 408222^2 .

It is a cyclic number.

It is not a de Polignac number, because 656680201909 - 2²¹ = 656678104757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656680202909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328340100954 + 328340100955.

It is an arithmetic number, because the mean of its divisors is an integer number (328340100955).

Almost surely, 2^656680201909 is an apocalyptic number.

It is an amenable number.

656680201909 is a deficient number, since it is larger than the sum of its proper divisors (1).

656680201909 is an equidigital number, since it uses as much as digits as its factorization.

656680201909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 52.

The spelling of 656680201909 in words is "six hundred fifty-six billion, six hundred eighty million, two hundred one thousand, nine hundred nine".