641631 has 16 divisors (see below), whose sum is σ = 946944. Its totient is φ = 384384.

The previous prime is 641623. The next prime is 641633. The reversal of 641631 is 136146.

It is not a de Polignac number, because 641631 - 2³ = 641623 is a prime.

It is a super-2 number, since 2×641631² = 823380680322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641598 and 641607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 900 + ... + 1446.

It is an arithmetic number, because the mean of its divisors is an integer number (59184).

2⁶⁴¹⁶³¹ is an apocalyptic number.

641631 is a deficient number, since it is larger than the sum of its proper divisors (305313).

641631 is a wasteful number, since it uses less digits than its factorization.

641631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590.

The product of its digits is 432, while the sum is 21.

The square root of 641631 is about 801.0187263729. The cubic root of 641631 is about 86.2505313977.

Adding to 641631 its reverse (136146), we get a palindrome (777777).

The spelling of 641631 in words is "six hundred forty-one thousand, six hundred thirty-one".