18918920812 has 24 divisors (see below), whose sum is σ = 36129062592. Its totient is φ = 8596861200.

The previous prime is 18918920789. The next prime is 18918920861. The reversal of 18918920812 is 21802981981.

It is a happy 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 7 ways as a sum of consecutive naturals, for example, 82023 + ... + 211105.

It is an arithmetic number, because the mean of its divisors is an integer number (1505377608).

Almost surely, 2^18918920812 is an apocalyptic number.

It is an amenable number.

18918920812 is a deficient number, since it is larger than the sum of its proper divisors (17210141780).

18918920812 is a wasteful number, since it uses less digits than its factorization.

18918920812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132429 (or 132427 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 49.

The spelling of 18918920812 in words is "eighteen billion, nine hundred eighteen million, nine hundred twenty thousand, eight hundred twelve".