997263561 has 16 divisors (see below), whose sum is σ = 1520943488. Its totient is φ = 569376000.

The previous prime is 997263557. The next prime is 997263593. The reversal of 997263561 is 165362799.

It is not a de Polignac number, because 997263561 - 2² = 997263557 is a prime.

It is a super-2 number, since 2×997263561² = 1989069220196801442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 997263561.

It is not an unprimeable number, because it can be changed into a prime (997263511) 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, 5451 + ... + 44991.

It is an arithmetic number, because the mean of its divisors is an integer number (95058968).

Almost surely, 2^997263561 is an apocalyptic number.

It is an amenable number.

997263561 is a deficient number, since it is larger than the sum of its proper divisors (523679927).

997263561 is a wasteful number, since it uses less digits than its factorization.

997263561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40752.

The product of its digits is 612360, while the sum is 48.

The square root of 997263561 is about 31579.4800622176. The cubic root of 997263561 is about 999.0870203886.

The spelling of 997263561 in words is "nine hundred ninety-seven million, two hundred sixty-three thousand, five hundred sixty-one".