997209131 has 2 divisors, whose sum is σ = 997209132. Its totient is φ = 997209130.

The previous prime is 997209071. The next prime is 997209149. The reversal of 997209131 is 131902799.

997209131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997209131 - 2¹⁸ = 996946987 is a prime.

It is a super-2 number, since 2×997209131² = 1988852101899550322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (997209931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498604565 + 498604566.

It is an arithmetic number, because the mean of its divisors is an integer number (498604566).

Almost surely, 2^997209131 is an apocalyptic number.

997209131 is a deficient number, since it is larger than the sum of its proper divisors (1).

997209131 is an equidigital number, since it uses as much as digits as its factorization.

997209131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 997209131 is about 31578.6182566622. The cubic root of 997209131 is about 999.0688435501.

The spelling of 997209131 in words is "nine hundred ninety-seven million, two hundred nine thousand, one hundred thirty-one".