13638213 has 20 divisors (see below), whose sum is σ = 20538540. Its totient is φ = 9018432.

The previous prime is 13638211. The next prime is 13638223. The reversal of 13638213 is 31283631.

It is a happy number.

13638213 is a `hidden beast` number, since 1 + 3 + 638 + 21 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11512449 + 2125764 = 3393^2 + 1458^2 .

It is not a de Polignac number, because 13638213 - 2¹ = 13638211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13638211) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10483 + ... + 11711.

It is an arithmetic number, because the mean of its divisors is an integer number (1026927).

Almost surely, 2^13638213 is an apocalyptic number.

It is an amenable number.

13638213 is a deficient number, since it is larger than the sum of its proper divisors (6900327).

13638213 is a wasteful number, since it uses less digits than its factorization.

13638213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378 (or 1369 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 13638213 is about 3692.9951259107. The cubic root of 13638213 is about 238.9199909588.

The spelling of 13638213 in words is "thirteen million, six hundred thirty-eight thousand, two hundred thirteen".