691080239 has 2 divisors, whose sum is σ = 691080240. Its totient is φ = 691080238.

The previous prime is 691080233. The next prime is 691080259. The reversal of 691080239 is 932080196.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 691080239 - 2²⁴ = 674303023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691080233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345540119 + 345540120.

It is an arithmetic number, because the mean of its divisors is an integer number (345540120).

Almost surely, 2^691080239 is an apocalyptic number.

691080239 is a deficient number, since it is larger than the sum of its proper divisors (1).

691080239 is an equidigital number, since it uses as much as digits as its factorization.

691080239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 691080239 is about 26288.4050295943. The cubic root of 691080239 is about 884.1164915278.

The spelling of 691080239 in words is "six hundred ninety-one million, eighty thousand, two hundred thirty-nine".