18939444500 has 24 divisors (see below), whose sum is σ = 41363747880. Its totient is φ = 7575777600.

The previous prime is 18939444487. The next prime is 18939444527. The reversal of 18939444500 is 544493981.

It can be written as a sum of positive squares in 4 ways, for example, as 178115716 + 18761328784 = 13346^2 + 136972^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18938945 + ... + 18939944.

It is an arithmetic number, because the mean of its divisors is an integer number (1723489495).

Almost surely, 2^18939444500 is an apocalyptic number.

18939444500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18939444500 is an abundant number, since it is smaller than the sum of its proper divisors (22424303380).

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

18939444500 is a wasteful number, since it uses less digits than its factorization.

18939444500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37878908 (or 37878896 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 18939444500 in words is "eighteen billion, nine hundred thirty-nine million, four hundred forty-four thousand, five hundred".