631665 has 16 divisors (see below), whose sum is σ = 1123200. Its totient is φ = 336816.

The previous prime is 631643. The next prime is 631667. The reversal of 631665 is 566136.

631665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 631665 - 2⁷ = 631537 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (631667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2205 + ... + 2474.

It is an arithmetic number, because the mean of its divisors is an integer number (70200).

2⁶³¹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

631665 is a deficient number, since it is larger than the sum of its proper divisors (491535).

631665 is a wasteful number, since it uses less digits than its factorization.

631665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4693 (or 4687 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 631665 is about 794.7735526551. The cubic root of 631665 is about 85.8016430807.

It can be divided in two parts, 631 and 665, that added together give a 4-th power (1296 = 6⁴).

The spelling of 631665 in words is "six hundred thirty-one thousand, six hundred sixty-five".