656726649 has 4 divisors (see below), whose sum is σ = 875635536. Its totient is φ = 437817764.

The previous prime is 656726617. The next prime is 656726669. The reversal of 656726649 is 946627656.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 656726649 - 2⁵ = 656726617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (656726669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109454439 + ... + 109454444.

It is an arithmetic number, because the mean of its divisors is an integer number (218908884).

Almost surely, 2^656726649 is an apocalyptic number.

It is an amenable number.

656726649 is a deficient number, since it is larger than the sum of its proper divisors (218908887).

656726649 is a wasteful number, since it uses less digits than its factorization.

656726649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218908886.

The product of its digits is 3265920, while the sum is 51.

The square root of 656726649 is about 25626.6784621027. The cubic root of 656726649 is about 869.2170032726.

The spelling of 656726649 in words is "six hundred fifty-six million, seven hundred twenty-six thousand, six hundred forty-nine".