690549689 has 2 divisors, whose sum is σ = 690549690. Its totient is φ = 690549688.

The previous prime is 690549683. The next prime is 690549697. The reversal of 690549689 is 986945096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 638421289 + 52128400 = 25267^2 + 7220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690549689 is a prime.

It is not a weakly prime, because it can be changed into another prime (690549683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345274844 + 345274845.

It is an arithmetic number, because the mean of its divisors is an integer number (345274845).

Almost surely, 2^690549689 is an apocalyptic number.

It is an amenable number.

690549689 is a deficient number, since it is larger than the sum of its proper divisors (1).

690549689 is an equidigital number, since it uses as much as digits as its factorization.

690549689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4199040, while the sum is 56.

The square root of 690549689 is about 26278.3121413838. The cubic root of 690549689 is about 883.8901849112.

The spelling of 690549689 in words is "six hundred ninety million, five hundred forty-nine thousand, six hundred eighty-nine".