691384867 has 2 divisors, whose sum is σ = 691384868. Its totient is φ = 691384866.

The previous prime is 691384823. The next prime is 691384873. The reversal of 691384867 is 768483196.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691384867 - 2⁷ = 691384739 is a prime.

It is not a weakly prime, because it can be changed into another prime (691384567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345692433 + 345692434.

It is an arithmetic number, because the mean of its divisors is an integer number (345692434).

Almost surely, 2^691384867 is an apocalyptic number.

691384867 is a deficient number, since it is larger than the sum of its proper divisors (1).

691384867 is an equidigital number, since it uses as much as digits as its factorization.

691384867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1741824, while the sum is 52.

The square root of 691384867 is about 26294.1983524883. The cubic root of 691384867 is about 884.2463785559.

The spelling of 691384867 in words is "six hundred ninety-one million, three hundred eighty-four thousand, eight hundred sixty-seven".