690638 has 16 divisors (see below), whose sum is σ = 1130976. Its totient is φ = 314400.

The previous prime is 690629. The next prime is 690661. The reversal of 690638 is 836096.

It is a happy number.

690638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 690638.

It is an unprimeable number.

690638 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2495 + ... + 2757.

It is an arithmetic number, because the mean of its divisors is an integer number (70686).

2⁶⁹⁰⁶³⁸ is an apocalyptic number.

690638 is a deficient number, since it is larger than the sum of its proper divisors (440338).

690638 is a wasteful number, since it uses less digits than its factorization.

690638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 690638 is about 831.0463284318. The cubic root of 690638 is about 88.3927862093.

The spelling of 690638 in words is "six hundred ninety thousand, six hundred thirty-eight".