656744623 has 4 divisors (see below), whose sum is σ = 656834560. Its totient is φ = 656654688.

The previous prime is 656744597. The next prime is 656744639. The reversal of 656744623 is 326447656.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 656744623 - 2⁵ = 656744591 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 656744623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (659744623) 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, 32943 + ... + 48976.

It is an arithmetic number, because the mean of its divisors is an integer number (164208640).

Almost surely, 2^656744623 is an apocalyptic number.

656744623 is a deficient number, since it is larger than the sum of its proper divisors (89937).

656744623 is an equidigital number, since it uses as much as digits as its factorization.

656744623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89936.

The product of its digits is 725760, while the sum is 43.

The square root of 656744623 is about 25627.0291489279. The cubic root of 656744623 is about 869.2249330883.

The spelling of 656744623 in words is "six hundred fifty-six million, seven hundred forty-four thousand, six hundred twenty-three".