690385 has 4 divisors (see below), whose sum is σ = 828468. Its totient is φ = 552304.

The previous prime is 690377. The next prime is 690397. The reversal of 690385 is 583096.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88209 + 602176 = 297^2 + 776^2 .

It is a cyclic number.

It is not a de Polignac number, because 690385 - 2³ = 690377 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69034 + ... + 69043.

It is an arithmetic number, because the mean of its divisors is an integer number (207117).

2⁶⁹⁰³⁸⁵ is an apocalyptic number.

It is an amenable number.

690385 is a deficient number, since it is larger than the sum of its proper divisors (138083).

690385 is a wasteful number, since it uses less digits than its factorization.

690385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138082.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 690385 is about 830.8940967416. The cubic root of 690385 is about 88.3819913084.

The spelling of 690385 in words is "six hundred ninety thousand, three hundred eighty-five".