491631 has 16 divisors (see below), whose sum is σ = 768768. Its totient is φ = 273600.

The previous prime is 491627. The next prime is 491633. The reversal of 491631 is 136194.

It is not a de Polignac number, because 491631 - 2² = 491627 is a prime.

It is a super-2 number, since 2×491631² = 483402080322, which contains 22 as substring.

491631 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491633) 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, 576 + ... + 1146.

It is an arithmetic number, because the mean of its divisors is an integer number (48048).

2⁴⁹¹⁶³¹ is an apocalyptic number.

491631 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

491631 is a deficient number, since it is larger than the sum of its proper divisors (277137).

491631 is a wasteful number, since it uses less digits than its factorization.

491631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622.

The product of its digits is 648, while the sum is 24.

The square root of 491631 is about 701.1640321637. The cubic root of 491631 is about 78.9247266767.

The spelling of 491631 in words is "four hundred ninety-one thousand, six hundred thirty-one".