13821631 has 6 divisors (see below), whose sum is σ = 14035560. Its totient is φ = 13610916.

The previous prime is 13821589. The next prime is 13821637. The reversal of 13821631 is 13612831.

It is not a de Polignac number, because 13821631 - 2⁷ = 13821503 is a prime.

It is a super-2 number, since 2×13821631² = 382074967000322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13821596 and 13821605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13821637) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2950 + ... + 6028.

It is an arithmetic number, because the mean of its divisors is an integer number (2339260).

Almost surely, 2^13821631 is an apocalyptic number.

13821631 is a deficient number, since it is larger than the sum of its proper divisors (213929).

13821631 is an frugal number, since it uses more digits than its factorization.

13821631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3213 (or 3146 counting only the distinct ones).

The product of its digits is 864, while the sum is 25.

The square root of 13821631 is about 3717.7454189334. The cubic root of 13821631 is about 239.9862897261.

The spelling of 13821631 in words is "thirteen million, eight hundred twenty-one thousand, six hundred thirty-one".