997536509 has 2 divisors, whose sum is σ = 997536510. Its totient is φ = 997536508.

The previous prime is 997536503. The next prime is 997536521. The reversal of 997536509 is 905635799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 985771609 + 11764900 = 31397^2 + 3430^2 .

It is a cyclic number.

It is not a de Polignac number, because 997536509 - 2⁴ = 997536493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997536503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498768254 + 498768255.

It is an arithmetic number, because the mean of its divisors is an integer number (498768255).

Almost surely, 2^997536509 is an apocalyptic number.

It is an amenable number.

997536509 is a deficient number, since it is larger than the sum of its proper divisors (1).

997536509 is an equidigital number, since it uses as much as digits as its factorization.

997536509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2296350, while the sum is 53.

The square root of 997536509 is about 31583.8013703227. The cubic root of 997536509 is about 999.1781610992.

The spelling of 997536509 in words is "nine hundred ninety-seven million, five hundred thirty-six thousand, five hundred nine".