690945361 has 4 divisors (see below), whose sum is σ = 691016292. Its totient is φ = 690874432.

The previous prime is 690945341. The next prime is 690945403. The reversal of 690945361 is 163549096.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 443355136 + 247590225 = 21056^2 + 15735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690945361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690945341) 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 in 3 ways as a sum of consecutive naturals, for example, 17980 + ... + 41293.

It is an arithmetic number, because the mean of its divisors is an integer number (172754073).

Almost surely, 2^690945361 is an apocalyptic number.

It is an amenable number.

690945361 is a deficient number, since it is larger than the sum of its proper divisors (70931).

690945361 is a wasteful number, since it uses less digits than its factorization.

690945361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70930.

The product of its (nonzero) digits is 174960, while the sum is 43.

The square root of 690945361 is about 26285.8395528847. The cubic root of 690945361 is about 884.0589701692.

The spelling of 690945361 in words is "six hundred ninety million, nine hundred forty-five thousand, three hundred sixty-one".