19221988 has 12 divisors (see below), whose sum is σ = 33685120. Its totient is φ = 9597672.

The previous prime is 19221971. The next prime is 19221991. The reversal of 19221988 is 88912291.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 19221988.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373 + ... + 6211.

Almost surely, 2^19221988 is an apocalyptic number.

It is an amenable number.

19221988 is a deficient number, since it is larger than the sum of its proper divisors (14463132).

19221988 is a wasteful number, since it uses less digits than its factorization.

19221988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6666 (or 6664 counting only the distinct ones).

The product of its digits is 20736, while the sum is 40.

The square root of 19221988 is about 4384.2887678619. The cubic root of 19221988 is about 267.8753597295.

The spelling of 19221988 in words is "nineteen million, two hundred twenty-one thousand, nine hundred eighty-eight".