656255621309 has 4 divisors (see below), whose sum is σ = 662753201820. Its totient is φ = 649758040800.

The previous prime is 656255621303. The next prime is 656255621341. The reversal of 656255621309 is 903126552656.

656255621309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 623157096409 + 33098524900 = 789403^2 + 181930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656255621309 is a prime.

It is a super-2 number, since 2×656255621309² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656255621303) 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, 3248790104 + ... + 3248790305.

It is an arithmetic number, because the mean of its divisors is an integer number (165688300455).

Almost surely, 2^656255621309 is an apocalyptic number.

It is an amenable number.

656255621309 is a deficient number, since it is larger than the sum of its proper divisors (6497580511).

656255621309 is a wasteful number, since it uses less digits than its factorization.

656255621309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6497580510.

The product of its (nonzero) digits is 2916000, while the sum is 50.

The spelling of 656255621309 in words is "six hundred fifty-six billion, two hundred fifty-five million, six hundred twenty-one thousand, three hundred nine".