691487959 has 2 divisors, whose sum is σ = 691487960. Its totient is φ = 691487958.

The previous prime is 691487947. The next prime is 691487963. The reversal of 691487959 is 959784196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691487959 - 2¹¹ = 691485911 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 (691487969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345743979 + 345743980.

It is an arithmetic number, because the mean of its divisors is an integer number (345743980).

Almost surely, 2^691487959 is an apocalyptic number.

691487959 is a deficient number, since it is larger than the sum of its proper divisors (1).

691487959 is an equidigital number, since it uses as much as digits as its factorization.

691487959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 58.

The square root of 691487959 is about 26296.1586358160. The cubic root of 691487959 is about 884.2903261947.

The spelling of 691487959 in words is "six hundred ninety-one million, four hundred eighty-seven thousand, nine hundred fifty-nine".