631618 has 16 divisors (see below), whose sum is σ = 1081080. Its totient is φ = 274176.

The previous prime is 631613. The next prime is 631619. The reversal of 631618 is 816136.

It can be written as a sum of positive squares in 4 ways, for example, as 368449 + 263169 = 607^2 + 513^2 .

It is a junction number, because it is equal to n+sod(n) for n = 631592 and 631601.

It is not an unprimeable number, because it can be changed into a prime (631613) by changing a digit.

631618 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, 273 + ... + 1156.

2⁶³¹⁶¹⁸ is an apocalyptic number.

631618 is a deficient number, since it is larger than the sum of its proper divisors (449462).

631618 is a wasteful number, since it uses less digits than its factorization.

631618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1461.

The product of its digits is 864, while the sum is 25.

The square root of 631618 is about 794.7439839344. The cubic root of 631618 is about 85.7995149604.

It can be divided in two parts, 63 and 1618, that added together give a square (1681 = 41²).

The spelling of 631618 in words is "six hundred thirty-one thousand, six hundred eighteen".