813779656 has 8 divisors (see below), whose sum is σ = 1525836870. Its totient is φ = 406889824.

The previous prime is 813779651. The next prime is 813779669. The reversal of 813779656 is 656977318.

It can be written as a sum of positive squares in only one way, i.e., 689902756 + 123876900 = 26266^2 + 11130^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (813779651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50861221 + ... + 50861236.

Almost surely, 2^813779656 is an apocalyptic number.

It is an amenable number.

813779656 is a deficient number, since it is larger than the sum of its proper divisors (712057214).

813779656 is a wasteful number, since it uses less digits than its factorization.

813779656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101722463 (or 101722459 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 52.

The square root of 813779656 is about 28526.8234474152. The cubic root of 813779656 is about 933.6174122789.

The spelling of 813779656 in words is "eight hundred thirteen million, seven hundred seventy-nine thousand, six hundred fifty-six".