812920880 has 80 divisors (see below), whose sum is σ = 1936081440. Its totient is φ = 317331456.

The previous prime is 812920877. The next prime is 812920897. The reversal of 812920880 is 88029218.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 740492 + ... + 741588.

It is an arithmetic number, because the mean of its divisors is an integer number (24201018).

Almost surely, 2^812920880 is an apocalyptic number.

812920880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 812920880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968040720).

812920880 is an abundant number, since it is smaller than the sum of its proper divisors (1123160560).

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

812920880 is a wasteful number, since it uses less digits than its factorization.

812920880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326 (or 1320 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 812920880 is about 28511.7673952353. The cubic root of 812920880 is about 933.2888833706.

The spelling of 812920880 in words is "eight hundred twelve million, nine hundred twenty thousand, eight hundred eighty".