19990188 has 36 divisors (see below), whose sum is σ = 51364768. Its totient is φ = 6553440.

The previous prime is 19990177. The next prime is 19990213. The reversal of 19990188 is 88109991.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2356 + ... + 6747.

Almost surely, 2^19990188 is an apocalyptic number.

19990188 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19990188 is an abundant number, since it is smaller than the sum of its proper divisors (31374580).

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

19990188 is a wasteful number, since it uses less digits than its factorization.

19990188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9174 (or 9169 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 45.

The square root of 19990188 is about 4471.0388054679. The cubic root of 19990188 is about 271.3973646222.

The spelling of 19990188 in words is "nineteen million, nine hundred ninety thousand, one hundred eighty-eight".