631439 has 4 divisors (see below), whose sum is σ = 651840. Its totient is φ = 611040.

The previous prime is 631429. The next prime is 631453. The reversal of 631439 is 934136.

631439 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 631439.

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 3 ways as a sum of consecutive naturals, for example, 10154 + ... + 10215.

It is an arithmetic number, because the mean of its divisors is an integer number (162960).

2⁶³¹⁴³⁹ is an apocalyptic number.

631439 is a deficient number, since it is larger than the sum of its proper divisors (20401).

631439 is a wasteful number, since it uses less digits than its factorization.

631439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20400.

The product of its digits is 1944, while the sum is 26.

The square root of 631439 is about 794.6313610725. The cubic root of 631439 is about 85.7914090249.

The spelling of 631439 in words is "six hundred thirty-one thousand, four hundred thirty-nine".