18398621444 has 12 divisors (see below), whose sum is σ = 36797242944. Its totient is φ = 7885123464.

The previous prime is 18398621393. The next prime is 18398621473. The reversal of 18398621444 is 44412689381.

18398621444 is an admirable number.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18398621392 and 18398621401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328546784 + ... + 328546839.

It is an arithmetic number, because the mean of its divisors is an integer number (3066436912).

Almost surely, 2^18398621444 is an apocalyptic number.

18398621444 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18398621444 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18398621444 is a wasteful number, since it uses less digits than its factorization.

18398621444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657093634 (or 657093632 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 50.

The spelling of 18398621444 in words is "eighteen billion, three hundred ninety-eight million, six hundred twenty-one thousand, four hundred forty-four".