811771980 has 24 divisors (see below), whose sum is σ = 2272961712. Its totient is φ = 216472512.

The previous prime is 811771967. The next prime is 811772063. The reversal of 811771980 is 89177118.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6764707 + ... + 6764826.

It is an arithmetic number, because the mean of its divisors is an integer number (94706738).

Almost surely, 2^811771980 is an apocalyptic number.

It is an amenable number.

811771980 is an abundant number, since it is smaller than the sum of its proper divisors (1461189732).

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

811771980 is a wasteful number, since it uses less digits than its factorization.

811771980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13529545 (or 13529543 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 42.

The square root of 811771980 is about 28491.6124499825. The cubic root of 811771980 is about 932.8490040988.

The spelling of 811771980 in words is "eight hundred eleven million, seven hundred seventy-one thousand, nine hundred eighty".