79980 has 48 divisors (see below), whose sum is σ = 236544. Its totient is φ = 20160.

The previous prime is 79979. The next prime is 79987. The reversal of 79980 is 8997.

79980 = 35² + 36² + ... + 65².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1839 + ... + 1881.

It is an arithmetic number, because the mean of its divisors is an integer number (4928).

2⁷⁹⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118272).

79980 is an abundant number, since it is smaller than the sum of its proper divisors (156564).

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

79980 is a wasteful number, since it uses less digits than its factorization.

79980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 79980 is about 282.8073549256. The cubic root of 79980 is about 43.0851027769.

The spelling of 79980 in words is "seventy-nine thousand, nine hundred eighty".