690165391 has 2 divisors, whose sum is σ = 690165392. Its totient is φ = 690165390.

The previous prime is 690165383. The next prime is 690165449. The reversal of 690165391 is 193561096.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 690165391 - 2³ = 690165383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690165361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345082695 + 345082696.

It is an arithmetic number, because the mean of its divisors is an integer number (345082696).

Almost surely, 2^690165391 is an apocalyptic number.

690165391 is a deficient number, since it is larger than the sum of its proper divisors (1).

690165391 is an equidigital number, since it uses as much as digits as its factorization.

690165391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 690165391 is about 26270.9990483803. Note that the first 3 decimals coincide. The cubic root of 690165391 is about 883.7261898280.

The spelling of 690165391 in words is "six hundred ninety million, one hundred sixty-five thousand, three hundred ninety-one".