997664 has 12 divisors (see below), whose sum is σ = 1964214. Its totient is φ = 498816.

The previous prime is 997663. The next prime is 997681. The reversal of 997664 is 466799.

It can be written as a sum of positive squares in only one way, i.e., 739600 + 258064 = 860^2 + 508^2 .

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (997663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15557 + ... + 15620.

2⁹⁹⁷⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

997664 is a deficient number, since it is larger than the sum of its proper divisors (966550).

997664 is a wasteful number, since it uses less digits than its factorization.

997664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31187 (or 31179 counting only the distinct ones).

The product of its digits is 81648, while the sum is 41.

The square root of 997664 is about 998.8313170901. The cubic root of 997664 is about 99.9220726223.

It can be divided in two parts, 997 and 664, that added together give a palindrome (1661).

The spelling of 997664 in words is "nine hundred ninety-seven thousand, six hundred sixty-four".