690401 has 4 divisors (see below), whose sum is σ = 712704. Its totient is φ = 668100.

The previous prime is 690397. The next prime is 690407. The reversal of 690401 is 104096.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 690401 - 2² = 690397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11105 + ... + 11166.

It is an arithmetic number, because the mean of its divisors is an integer number (178176).

2⁶⁹⁰⁴⁰¹ is an apocalyptic number.

It is an amenable number.

690401 is a deficient number, since it is larger than the sum of its proper divisors (22303).

690401 is a wasteful number, since it uses less digits than its factorization.

690401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22302.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 690401 is about 830.9037248683. The cubic root of 690401 is about 88.3826740680.

Adding to 690401 its reverse (104096), we get a palindrome (794497).

The spelling of 690401 in words is "six hundred ninety thousand, four hundred one".