813866772 has 72 divisors (see below), whose sum is σ = 2026249120. Its totient is φ = 254200320.

The previous prime is 813866743. The next prime is 813866791. The reversal of 813866772 is 277668318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1147554 + ... + 1148262.

Almost surely, 2^813866772 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813866772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013124560).

813866772 is an abundant number, since it is smaller than the sum of its proper divisors (1212382348).

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

813866772 is a wasteful number, since it uses less digits than its factorization.

813866772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081 (or 1062 counting only the distinct ones).

The product of its digits is 677376, while the sum is 48.

The square root of 813866772 is about 28528.3503203392. The cubic root of 813866772 is about 933.6507260110.

The spelling of 813866772 in words is "eight hundred thirteen million, eight hundred sixty-six thousand, seven hundred seventy-two".