656213205649 has 2 divisors, whose sum is σ = 656213205650. Its totient is φ = 656213205648.

The previous prime is 656213205647. The next prime is 656213205673. The reversal of 656213205649 is 946502312656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 656088660049 + 124545600 = 809993^2 + 11160^2 .

It is a cyclic number.

It is not a de Polignac number, because 656213205649 - 2¹ = 656213205647 is a prime.

It is a super-2 number, since 2×656213205649² (a number of 24 digits) contains 22 as substring.

Together with 656213205647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (656213205647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328106602824 + 328106602825.

It is an arithmetic number, because the mean of its divisors is an integer number (328106602825).

Almost surely, 2^656213205649 is an apocalyptic number.

It is an amenable number.

656213205649 is a deficient number, since it is larger than the sum of its proper divisors (1).

656213205649 is an equidigital number, since it uses as much as digits as its factorization.

656213205649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2332800, while the sum is 49.

The spelling of 656213205649 in words is "six hundred fifty-six billion, two hundred thirteen million, two hundred five thousand, six hundred forty-nine".