19980900 has 81 divisors (see below), whose sum is σ = 63052171. Its totient is φ = 5292480.

The previous prime is 19980889. The next prime is 19980907. The reversal of 19980900 is 908991.

The square root of 19980900 is 4470.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 5963364 + 14017536 = 2442^2 + 3744^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19980907) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 134026 + ... + 134174.

Almost surely, 2^19980900 is an apocalyptic number.

19980900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19980900 is the 4470-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19980900

19980900 is an abundant number, since it is smaller than the sum of its proper divisors (43071271).

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

19980900 is a wasteful number, since it uses less digits than its factorization.

19980900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The cubic root of 19980900 is about 271.3553251772.

Multiplying 19980900 by its sum of digits (36), we get a square (719312400 = 26820²).

19980900 divided by its sum of digits (36) gives a square (555025 = 745²).

The spelling of 19980900 in words is "nineteen million, nine hundred eighty thousand, nine hundred".