815923921922 has 6 divisors (see below), whose sum is σ = 1223887799043.
Its totient is φ = 407961322242.
The previous prime is 815923921867. The next prime is 815923921931. The reversal of 815923921922 is 229129329518.
It can be written as a sum of positive squares in only one way, i.e., 407961960961 + 407961960961 = 638719^2 + 638719^2
It is an ABA number since it can be written as A⋅BA, here for A=2, B=638719.
It is a Duffinian number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (19) of ones.
It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 958079 + ... + 1596797.
Almost surely, 2815923921922 is an apocalyptic number.
815923921922 is a deficient number, since it is larger than the sum of its proper divisors (407963877121).
815923921922 is an frugal number, since it uses more digits than its factorization.
815923921922 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1277440 (or 638721 counting only the distinct ones).
The product of its digits is 1399680, while the sum is 53.
The spelling of 815923921922 in words is "eight hundred fifteen billion, nine hundred twenty-three million, nine hundred twenty-one thousand, nine hundred twenty-two".