19987972 has 12 divisors (see below), whose sum is σ = 35723520. Its totient is φ = 9781256.

The previous prime is 19987969. The next prime is 19987993. The reversal of 19987972 is 27978991.

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, 52972 + ... + 53347.

It is an arithmetic number, because the mean of its divisors is an integer number (2976960).

Almost surely, 2^19987972 is an apocalyptic number.

It is an amenable number.

19987972 is a deficient number, since it is larger than the sum of its proper divisors (15735548).

19987972 is a wasteful number, since it uses less digits than its factorization.

19987972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106370 (or 106368 counting only the distinct ones).

The product of its digits is 571536, while the sum is 52.

The square root of 19987972 is about 4470.7909814707. The cubic root of 19987972 is about 271.3873357223.

The spelling of 19987972 in words is "nineteen million, nine hundred eighty-seven thousand, nine hundred seventy-two".