19889970 has 16 divisors (see below), whose sum is σ = 47736000. Its totient is φ = 5303984.

The previous prime is 19889957. The next prime is 19889981. The reversal of 19889970 is 7998891.

It is a super-2 number, since 2×19889970² = 791221813201800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331470 + ... + 331529.

It is an arithmetic number, because the mean of its divisors is an integer number (2983500).

Almost surely, 2^19889970 is an apocalyptic number.

19889970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19889970 is an abundant number, since it is smaller than the sum of its proper divisors (27846030).

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

19889970 is a wasteful number, since it uses less digits than its factorization.

19889970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663009.

The product of its (nonzero) digits is 326592, while the sum is 51.

The square root of 19889970 is about 4459.8172608303. The cubic root of 19889970 is about 270.9430670650.

The spelling of 19889970 in words is "nineteen million, eight hundred eighty-nine thousand, nine hundred seventy".