691994899 has 2 divisors, whose sum is σ = 691994900. Its totient is φ = 691994898.

The previous prime is 691994887. The next prime is 691994903. The reversal of 691994899 is 998499196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691994899 - 2²³ = 683606291 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 691994899.

It is not a weakly prime, because it can be changed into another prime (691994819) 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, 345997449 + 345997450.

It is an arithmetic number, because the mean of its divisors is an integer number (345997450).

Almost surely, 2^691994899 is an apocalyptic number.

691994899 is a deficient number, since it is larger than the sum of its proper divisors (1).

691994899 is an equidigital number, since it uses as much as digits as its factorization.

691994899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11337408, while the sum is 64.

The square root of 691994899 is about 26305.7959202910. The cubic root of 691994899 is about 884.5063688263.

The spelling of 691994899 in words is "six hundred ninety-one million, nine hundred ninety-four thousand, eight hundred ninety-nine".