631405 has 8 divisors (see below), whose sum is σ = 778392. Its totient is φ = 491328.

The previous prime is 631399. The next prime is 631409. The reversal of 631405 is 504136.

631405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 338724 + 292681 = 582^2 + 541^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 631405 - 2⁹ = 630893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1522 + ... + 1891.

It is an arithmetic number, because the mean of its divisors is an integer number (97299).

2⁶³¹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

631405 is a deficient number, since it is larger than the sum of its proper divisors (146987).

631405 is a wasteful number, since it uses less digits than its factorization.

631405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3455.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 631405 is about 794.6099672166. The cubic root of 631405 is about 85.7898691769.

The spelling of 631405 in words is "six hundred thirty-one thousand, four hundred five".