19939980 has 96 divisors (see below), whose sum is σ = 59984064. Its totient is φ = 4931584.

The previous prime is 19939973. The next prime is 19939993. The reversal of 19939980 is 8993991.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115174 + ... + 115346.

It is an arithmetic number, because the mean of its divisors is an integer number (624834).

Almost surely, 2^19939980 is an apocalyptic number.

19939980 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 19939980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29992032).

19939980 is an abundant number, since it is smaller than the sum of its proper divisors (40044084).

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

19939980 is a wasteful number, since it uses less digits than its factorization.

19939980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 313 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 48.

The square root of 19939980 is about 4465.4204729230. The cubic root of 19939980 is about 271.1699573407.

The spelling of 19939980 in words is "nineteen million, nine hundred thirty-nine thousand, nine hundred eighty".