631685 has 4 divisors (see below), whose sum is σ = 758028. Its totient is φ = 505344.

The previous prime is 631681. The next prime is 631711. The reversal of 631685 is 586136.

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 417316 + 214369 = 646^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 631685 - 2² = 631681 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 (631681) 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, 63164 + ... + 63173.

It is an arithmetic number, because the mean of its divisors is an integer number (189507).

2⁶³¹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

631685 is a deficient number, since it is larger than the sum of its proper divisors (126343).

631685 is a wasteful number, since it uses less digits than its factorization.

631685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126342.

The product of its digits is 4320, while the sum is 29.

The square root of 631685 is about 794.7861347558. The cubic root of 631685 is about 85.8025486317.

The spelling of 631685 in words is "six hundred thirty-one thousand, six hundred eighty-five".