19989700 has 72 divisors (see below), whose sum is σ = 46012680. Its totient is φ = 7526400.

The previous prime is 19989689. The next prime is 19989701. The reversal of 19989700 is 798991.

It can be written as a sum of positive squares in 12 ways, for example, as 16662724 + 3326976 = 4082^2 + 1824^2 .

It is not an unprimeable number, because it can be changed into a prime (19989701) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 176844 + ... + 176956.

It is an arithmetic number, because the mean of its divisors is an integer number (639065).

Almost surely, 2^19989700 is an apocalyptic number.

19989700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19989700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23006340).

19989700 is an abundant number, since it is smaller than the sum of its proper divisors (26022980).

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

19989700 is a wasteful number, since it uses less digits than its factorization.

19989700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 19989700 is about 4470.9842316877. The cubic root of 19989700 is about 271.3951561555.

The spelling of 19989700 in words is "nineteen million, nine hundred eighty-nine thousand, seven hundred".