997181280 has 120 divisors (see below), whose sum is σ = 3519264672. Its totient is φ = 265911552.

The previous prime is 997181231. The next prime is 997181299. The reversal of 997181280 is 82181799.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 25512 + ... + 51431.

Almost surely, 2^997181280 is an apocalyptic number.

997181280 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

997181280 is an abundant number, since it is smaller than the sum of its proper divisors (2522083392).

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

997181280 is a wasteful number, since it uses less digits than its factorization.

997181280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76970 (or 76953 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 45.

The square root of 997181280 is about 31578.1772748207. The cubic root of 997181280 is about 999.0595424836.

The spelling of 997181280 in words is "nine hundred ninety-seven million, one hundred eighty-one thousand, two hundred eighty".