812491507780 has 24 divisors (see below), whose sum is σ = 1752346550808. Its totient is φ = 316212910848.

The previous prime is 812491507769. The next prime is 812491507799. The reversal of 812491507780 is 87705194218.

It can be written as a sum of positive squares in 4 ways, for example, as 46176852544 + 766314655236 = 214888^2 + 875394^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 548980009 + ... + 548981488.

It is an arithmetic number, because the mean of its divisors is an integer number (73014439617).

Almost surely, 2^812491507780 is an apocalyptic number.

It is an amenable number.

812491507780 is an abundant number, since it is smaller than the sum of its proper divisors (939855043028).

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

812491507780 is a wasteful number, since it uses less digits than its factorization.

812491507780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097961543 (or 1097961541 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 52.

The spelling of 812491507780 in words is "eight hundred twelve billion, four hundred ninety-one million, five hundred seven thousand, seven hundred eighty".