18420398788 has 24 divisors (see below), whose sum is σ = 35258065920. Its totient is φ = 8351039520.

The previous prime is 18420398771. The next prime is 18420398831. The reversal of 18420398788 is 88789302481.

It is a super-2 number, since 2×18420398788² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 529683 + ... + 563386.

It is an arithmetic number, because the mean of its divisors is an integer number (1469086080).

Almost surely, 2^18420398788 is an apocalyptic number.

It is an amenable number.

18420398788 is a deficient number, since it is larger than the sum of its proper divisors (16837667132).

18420398788 is a wasteful number, since it uses less digits than its factorization.

18420398788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093467 (or 1093465 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 58.

The spelling of 18420398788 in words is "eighteen billion, four hundred twenty million, three hundred ninety-eight thousand, seven hundred eighty-eight".