31638631 has 8 divisors (see below), whose sum is σ = 33075200. Its totient is φ = 30228120.

The previous prime is 31638611. The next prime is 31638653. The reversal of 31638631 is 13683613.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31638631 - 2⁵ = 31638599 is a prime.

It is a super-2 number, since 2×31638631² = 2002005943108322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31638593 and 31638602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31638601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4011 + ... + 8908.

It is an arithmetic number, because the mean of its divisors is an integer number (4134400).

Almost surely, 2^31638631 is an apocalyptic number.

31638631 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

31638631 is a deficient number, since it is larger than the sum of its proper divisors (1436569).

31638631 is a wasteful number, since it uses less digits than its factorization.

31638631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13029.

The product of its digits is 7776, while the sum is 31.

The square root of 31638631 is about 5624.8227527630. The cubic root of 31638631 is about 316.2806051817.

The spelling of 31638631 in words is "thirty-one million, six hundred thirty-eight thousand, six hundred thirty-one".