690989009 has 2 divisors, whose sum is σ = 690989010. Its totient is φ = 690989008.

The previous prime is 690988957. The next prime is 690989077. The reversal of 690989009 is 900989096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 658179025 + 32809984 = 25655^2 + 5728^2 .

It is a cyclic number.

It is not a de Polignac number, because 690989009 - 2²⁸ = 422553553 is a prime.

It is not a weakly prime, because it can be changed into another prime (690989609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345494504 + 345494505.

It is an arithmetic number, because the mean of its divisors is an integer number (345494505).

Almost surely, 2^690989009 is an apocalyptic number.

It is an amenable number.

690989009 is a deficient number, since it is larger than the sum of its proper divisors (1).

690989009 is an equidigital number, since it uses as much as digits as its factorization.

690989009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 314928, while the sum is 50.

The square root of 690989009 is about 26286.6697966859. The cubic root of 690989009 is about 884.0775855308.

The spelling of 690989009 in words is "six hundred ninety million, nine hundred eighty-nine thousand, nine".