813043778 has 8 divisors (see below), whose sum is σ = 1236272268. Its totient is φ = 400953024.

The previous prime is 813043769. The next prime is 813043783. The reversal of 813043778 is 877340318.

It can be written as a sum of positive squares in 2 ways, for example, as 743271169 + 69772609 = 27263^2 + 8353^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×813043778² = 1322080369889026568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2784251 + ... + 2784542.

Almost surely, 2^813043778 is an apocalyptic number.

813043778 is a deficient number, since it is larger than the sum of its proper divisors (423228490).

813043778 is a wasteful number, since it uses less digits than its factorization.

813043778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5568868.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 813043778 is about 28513.9225291786. The cubic root of 813043778 is about 933.3359127763.

The spelling of 813043778 in words is "eight hundred thirteen million, forty-three thousand, seven hundred seventy-eight".