813943656 has 24 divisors (see below), whose sum is σ = 2204430930. Its totient is φ = 271314528.

The previous prime is 813943643. The next prime is 813943661. The reversal of 813943656 is 656349318.

It can be written as a sum of positive squares in only one way, i.e., 798966756 + 14976900 = 28266^2 + 3870^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5652315 + ... + 5652458.

Almost surely, 2^813943656 is an apocalyptic number.

It is an amenable number.

813943656 is an abundant number, since it is smaller than the sum of its proper divisors (1390487274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

813943656 is a wasteful number, since it uses less digits than its factorization.

813943656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11304785 (or 11304778 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 813943656 is about 28529.6977901975. The cubic root of 813943656 is about 933.6801249841.

The spelling of 813943656 in words is "eight hundred thirteen million, nine hundred forty-three thousand, six hundred fifty-six".