631138 has 4 divisors (see below), whose sum is σ = 946710. Its totient is φ = 315568.

The previous prime is 631133. The next prime is 631139. The reversal of 631138 is 831136.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 588289 + 42849 = 767^2 + 207^2 .

It is not an unprimeable number, because it can be changed into a prime (631133) by changing a digit.

631138 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 as a sum of consecutive naturals, namely, 157783 + ... + 157786.

2⁶³¹¹³⁸ is an apocalyptic number.

631138 is a deficient number, since it is larger than the sum of its proper divisors (315572).

631138 is a wasteful number, since it uses less digits than its factorization.

631138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315571.

The product of its digits is 432, while the sum is 22.

The square root of 631138 is about 794.4419424980. The cubic root of 631138 is about 85.7777749191. Note that the first 5 decimals are identical.

It can be divided in two parts, 631 and 138, that multiplied together give a palindrome (87078).

The spelling of 631138 in words is "six hundred thirty-one thousand, one hundred thirty-eight".