997138139 has 2 divisors, whose sum is σ = 997138140. Its totient is φ = 997138138.

The previous prime is 997138127. The next prime is 997138169. The reversal of 997138139 is 931831799.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997138139 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (997138169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498569069 + 498569070.

It is an arithmetic number, because the mean of its divisors is an integer number (498569070).

Almost surely, 2^997138139 is an apocalyptic number.

997138139 is a deficient number, since it is larger than the sum of its proper divisors (1).

997138139 is an equidigital number, since it uses as much as digits as its factorization.

997138139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 50.

The square root of 997138139 is about 31577.4941849413. The cubic root of 997138139 is about 999.0451348561.

The spelling of 997138139 in words is "nine hundred ninety-seven million, one hundred thirty-eight thousand, one hundred thirty-nine".