812879920 has 20 divisors (see below), whose sum is σ = 1889946000. Its totient is φ = 325151936.

The previous prime is 812879897. The next prime is 812879929. The reversal of 812879920 is 29978218.

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

It is not an unprimeable number, because it can be changed into a prime (812879929) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5080420 + ... + 5080579.

It is an arithmetic number, because the mean of its divisors is an integer number (94497300).

Almost surely, 2^812879920 is an apocalyptic number.

812879920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812879920 is an abundant number, since it is smaller than the sum of its proper divisors (1077066080).

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

812879920 is a wasteful number, since it uses less digits than its factorization.

812879920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10161012 (or 10161006 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 812879920 is about 28511.0490862753. The cubic root of 812879920 is about 933.2732081450.

The spelling of 812879920 in words is "eight hundred twelve million, eight hundred seventy-nine thousand, nine hundred twenty".