691542499 has 2 divisors, whose sum is σ = 691542500. Its totient is φ = 691542498.

The previous prime is 691542413. The next prime is 691542521. The reversal of 691542499 is 994245196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691542499 - 2⁹ = 691541987 is a prime.

It is not a weakly prime, because it can be changed into another prime (691542799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345771249 + 345771250.

It is an arithmetic number, because the mean of its divisors is an integer number (345771250).

Almost surely, 2^691542499 is an apocalyptic number.

691542499 is a deficient number, since it is larger than the sum of its proper divisors (1).

691542499 is an equidigital number, since it uses as much as digits as its factorization.

691542499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 49.

The square root of 691542499 is about 26297.1956489661. The cubic root of 691542499 is about 884.3135745756.

The spelling of 691542499 in words is "six hundred ninety-one million, five hundred forty-two thousand, four hundred ninety-nine".