690573409 has 2 divisors, whose sum is σ = 690573410. Its totient is φ = 690573408.

The previous prime is 690573407. The next prime is 690573427. The reversal of 690573409 is 904375096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 683299600 + 7273809 = 26140^2 + 2697^2 .

It is a cyclic number.

It is not a de Polignac number, because 690573409 - 2¹ = 690573407 is a prime.

Together with 690573407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (690573407) 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, 345286704 + 345286705.

It is an arithmetic number, because the mean of its divisors is an integer number (345286705).

Almost surely, 2^690573409 is an apocalyptic number.

It is an amenable number.

690573409 is a deficient number, since it is larger than the sum of its proper divisors (1).

690573409 is an equidigital number, since it uses as much as digits as its factorization.

690573409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 43.

The square root of 690573409 is about 26278.7634602544. The cubic root of 690573409 is about 883.9003051750.

The spelling of 690573409 in words is "six hundred ninety million, five hundred seventy-three thousand, four hundred nine".