997738569 has 9 divisors (see below), whose sum is σ = 1441314823. Its totient is φ = 665095872.

The previous prime is 997738561. The next prime is 997738579. The reversal of 997738569 is 965837799.

The square root of 997738569 is 31587.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 807298569 + 190440000 = 28413^2 + 13800^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 997738569 - 2³ = 997738561 is a prime.

It is a super-2 number, since 2×997738569² = 1990964504140335522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (997738561) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 89497 + ... + 100025.

Almost surely, 2^997738569 is an apocalyptic number.

997738569 is the 31587-th square number.

997738569 is the 15794-th centered octagonal number.

It is an amenable number.

997738569 is a deficient number, since it is larger than the sum of its proper divisors (443576254).

997738569 is an frugal number, since it uses more digits than its factorization.

997738569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21064 (or 10532 counting only the distinct ones).

The product of its digits is 25719120, while the sum is 63.

The cubic root of 997738569 is about 999.2456207217.

The spelling of 997738569 in words is "nine hundred ninety-seven million, seven hundred thirty-eight thousand, five hundred sixty-nine".