997540864 has 22 divisors (see below), whose sum is σ = 1994109614. Its totient is φ = 498769920.

The previous prime is 997540861. The next prime is 997540877. The reversal of 997540864 is 468045799.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 864830464 + 132710400 = 29408^2 + 11520^2 .

It is not an unprimeable number, because it can be changed into a prime (997540861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 486057 + ... + 488104.

Almost surely, 2^997540864 is an apocalyptic number.

It is an amenable number.

997540864 is a deficient number, since it is larger than the sum of its proper divisors (996568750).

997540864 is an equidigital number, since it uses as much as digits as its factorization.

997540864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974181 (or 974163 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 52.

The square root of 997540864 is about 31583.8703138168. The cubic root of 997540864 is about 999.1796151528.

The spelling of 997540864 in words is "nine hundred ninety-seven million, five hundred forty thousand, eight hundred sixty-four".