631321 has 4 divisors (see below), whose sum is σ = 633652. Its totient is φ = 628992.

The previous prime is 631307. The next prime is 631339. The reversal of 631321 is 123136.

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 215296 + 416025 = 464^2 + 645^2 .

It is a cyclic number.

It is not a de Polignac number, because 631321 - 2¹⁷ = 500249 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 631295 and 631304.

It is not an unprimeable number, because it can be changed into a prime (631361) 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, 696 + ... + 1321.

It is an arithmetic number, because the mean of its divisors is an integer number (158413).

2⁶³¹³²¹ is an apocalyptic number.

It is an amenable number.

631321 is a deficient number, since it is larger than the sum of its proper divisors (2331).

631321 is a wasteful number, since it uses less digits than its factorization.

631321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2330.

The product of its digits is 108, while the sum is 16.

The square root of 631321 is about 794.5571093383. The cubic root of 631321 is about 85.7860646096.

Adding to 631321 its reverse (123136), we get a palindrome (754457).

The spelling of 631321 in words is "six hundred thirty-one thousand, three hundred twenty-one".