997980 has 24 divisors (see below), whose sum is σ = 2794512. Its totient is φ = 266112.

The previous prime is 997973. The next prime is 997991. The reversal of 997980 is 89799.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8257 + ... + 8376.

It is an arithmetic number, because the mean of its divisors is an integer number (116438).

2⁹⁹⁷⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

997980 is an abundant number, since it is smaller than the sum of its proper divisors (1796532).

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

997980 is a wasteful number, since it uses less digits than its factorization.

997980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16645 (or 16643 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 42.

The square root of 997980 is about 998.9894894342. The cubic root of 997980 is about 99.9326212779.

The spelling of 997980 in words is "nine hundred ninety-seven thousand, nine hundred eighty".