19311920 has 40 divisors (see below), whose sum is σ = 45111696. Its totient is φ = 7688448.

The previous prime is 19311913. The next prime is 19311937. The reversal of 19311920 is 2911391.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 19311920.

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 7 ways as a sum of consecutive naturals, for example, 22214 + ... + 23066.

Almost surely, 2^19311920 is an apocalyptic number.

19311920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19311920 is an abundant number, since it is smaller than the sum of its proper divisors (25799776).

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

19311920 is a wasteful number, since it uses less digits than its factorization.

19311920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149 (or 1143 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 19311920 is about 4394.5329672219. The cubic root of 19311920 is about 268.2924704910.

The spelling of 19311920 in words is "nineteen million, three hundred eleven thousand, nine hundred twenty".