981631 has 16 divisors (see below), whose sum is σ = 1214784. Its totient is φ = 774144.

The previous prime is 981623. The next prime is 981637. The reversal of 981631 is 136189.

It is a happy number.

It is not a de Polignac number, because 981631 - 2³ = 981623 is a prime.

It is a super-2 number, since 2×981631² = 1927198840322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 981631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981637) 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, 8631 + ... + 8743.

It is an arithmetic number, because the mean of its divisors is an integer number (75924).

2⁹⁸¹⁶³¹ is an apocalyptic number.

981631 is a deficient number, since it is larger than the sum of its proper divisors (233153).

981631 is a wasteful number, since it uses less digits than its factorization.

981631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210.

The product of its digits is 1296, while the sum is 28.

The square root of 981631 is about 990.7729305951. The cubic root of 981631 is about 99.3839121525.

The spelling of 981631 in words is "nine hundred eighty-one thousand, six hundred thirty-one".