690481657 has 2 divisors, whose sum is σ = 690481658. Its totient is φ = 690481656.

The previous prime is 690481637. The next prime is 690481691. The reversal of 690481657 is 756184096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 546577641 + 143904016 = 23379^2 + 11996^2 .

It is a cyclic number.

It is not a de Polignac number, because 690481657 - 2¹¹ = 690479609 is a prime.

It is not a weakly prime, because it can be changed into another prime (690481607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345240828 + 345240829.

It is an arithmetic number, because the mean of its divisors is an integer number (345240829).

Almost surely, 2^690481657 is an apocalyptic number.

It is an amenable number.

690481657 is a deficient number, since it is larger than the sum of its proper divisors (1).

690481657 is an equidigital number, since it uses as much as digits as its factorization.

690481657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 690481657 is about 26277.0176580220. The cubic root of 690481657 is about 883.8611574119.

The spelling of 690481657 in words is "six hundred ninety million, four hundred eighty-one thousand, six hundred fifty-seven".