690259991 has 2 divisors, whose sum is σ = 690259992. Its totient is φ = 690259990.

The previous prime is 690259967. The next prime is 690260009. The reversal of 690259991 is 199952096.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 690259991 - 2²⁶ = 623151127 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 (690159991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345129995 + 345129996.

It is an arithmetic number, because the mean of its divisors is an integer number (345129996).

Almost surely, 2^690259991 is an apocalyptic number.

690259991 is a deficient number, since it is larger than the sum of its proper divisors (1).

690259991 is an equidigital number, since it uses as much as digits as its factorization.

690259991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 393660, while the sum is 50.

The square root of 690259991 is about 26272.7994511434. The cubic root of 690259991 is about 883.7665650189.

The spelling of 690259991 in words is "six hundred ninety million, two hundred fifty-nine thousand, nine hundred ninety-one".