812997520 has 20 divisors (see below), whose sum is σ = 1890219420. Its totient is φ = 325198976.

The previous prime is 812997473. The next prime is 812997541. The reversal of 812997520 is 25799218.

It can be written as a sum of positive squares in 2 ways, for example, as 576576144 + 236421376 = 24012^2 + 15376^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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, 5081155 + ... + 5081314.

It is an arithmetic number, because the mean of its divisors is an integer number (94510971).

Almost surely, 2^812997520 is an apocalyptic number.

812997520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812997520 is an abundant number, since it is smaller than the sum of its proper divisors (1077221900).

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

812997520 is a wasteful number, since it uses less digits than its factorization.

812997520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10162482 (or 10162476 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 812997520 is about 28513.1113700347. Note that the first 3 decimals coincide. The cubic root of 812997520 is about 933.3182117731.

The spelling of 812997520 in words is "eight hundred twelve million, nine hundred ninety-seven thousand, five hundred twenty".