18929721920 has 28 divisors (see below), whose sum is σ = 45076401084. Its totient is φ = 7571888640.

The previous prime is 18929721883. The next prime is 18929721997. The reversal of 18929721920 is 2912792981.

It can be written as a sum of positive squares in 2 ways, for example, as 2784461824 + 16145260096 = 52768^2 + 127064^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29577371 + ... + 29578010.

Almost surely, 2^18929721920 is an apocalyptic number.

18929721920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18929721920 is an abundant number, since it is smaller than the sum of its proper divisors (26146679164).

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

18929721920 is an equidigital number, since it uses as much as digits as its factorization.

18929721920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59155398 (or 59155388 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 50.

The spelling of 18929721920 in words is "eighteen billion, nine hundred twenty-nine million, seven hundred twenty-one thousand, nine hundred twenty".