813287256621 has 32 divisors (see below), whose sum is σ = 1248834060288. Its totient is φ = 461161061760.

The previous prime is 813287256571. The next prime is 813287256629. The reversal of 813287256621 is 126652782318.

It is not a de Polignac number, because 813287256621 - 2¹⁰ = 813287255597 is a prime.

It is a super-2 number, since 2×813287256621² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813287256629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7399756 + ... + 7508858.

It is an arithmetic number, because the mean of its divisors is an integer number (39026064384).

Almost surely, 2^813287256621 is an apocalyptic number.

It is an amenable number.

813287256621 is a deficient number, since it is larger than the sum of its proper divisors (435546803667).

813287256621 is a wasteful number, since it uses less digits than its factorization.

813287256621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111841.

The product of its digits is 1935360, while the sum is 51.

The spelling of 813287256621 in words is "eight hundred thirteen billion, two hundred eighty-seven million, two hundred fifty-six thousand, six hundred twenty-one".