812808720 has 60 divisors (see below), whose sum is σ = 2729685036. Its totient is φ = 216748800.

The previous prime is 812808697. The next prime is 812808739. The reversal of 812808720 is 27808218.

It can be written as a sum of positive squares in 2 ways, for example, as 566820864 + 245987856 = 23808^2 + 15684^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 563731 + ... + 565170.

Almost surely, 2^812808720 is an apocalyptic number.

812808720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812808720 is an abundant number, since it is smaller than the sum of its proper divisors (1916876316).

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

812808720 is a wasteful number, since it uses less digits than its factorization.

812808720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128920 (or 1128911 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 812808720 is about 28509.8004202064. The cubic root of 812808720 is about 933.2459589408.

It can be divided in two parts, 81280 and 8720, that added together give a square (90000 = 300²).

The spelling of 812808720 in words is "eight hundred twelve million, eight hundred eight thousand, seven hundred twenty".