631643 has 2 divisors, whose sum is σ = 631644. Its totient is φ = 631642.

The previous prime is 631619. The next prime is 631667. The reversal of 631643 is 346136.

It is a balanced prime because it is at equal distance from previous prime (631619) and next prime (631667).

It is a cyclic number.

It is not a de Polignac number, because 631643 - 2⁸ = 631387 is a prime.

It is not a weakly prime, because it can be changed into another prime (631613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315821 + 315822.

It is an arithmetic number, because the mean of its divisors is an integer number (315822).

2⁶³¹⁶⁴³ is an apocalyptic number.

631643 is a deficient number, since it is larger than the sum of its proper divisors (1).

631643 is an equidigital number, since it uses as much as digits as its factorization.

631643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 23.

The square root of 631643 is about 794.7597121143. The cubic root of 631643 is about 85.8006469524.

Adding to 631643 its reverse (346136), we get a palindrome (977779).

The spelling of 631643 in words is "six hundred thirty-one thousand, six hundred forty-three".