18979980 has 48 divisors (see below), whose sum is σ = 53555040. Its totient is φ = 5022208.

The previous prime is 18979957. The next prime is 18979999. The reversal of 18979980 is 8997981.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7066 + ... + 9374.

It is an arithmetic number, because the mean of its divisors is an integer number (1115730).

Almost surely, 2^18979980 is an apocalyptic number.

18979980 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 18979980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26777520).

18979980 is an abundant number, since it is smaller than the sum of its proper divisors (34575060).

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

18979980 is a wasteful number, since it uses less digits than its factorization.

18979980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2458 (or 2456 counting only the distinct ones).

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

The square root of 18979980 is about 4356.6018867920. The cubic root of 18979980 is about 266.7464101790.

The spelling of 18979980 in words is "eighteen million, nine hundred seventy-nine thousand, nine hundred eighty".