13551321 has 24 divisors (see below), whose sum is σ = 21201600. Its totient is φ = 7541856.

The previous prime is 13551319. The next prime is 13551337. The reversal of 13551321 is 12315531.

It is not a de Polignac number, because 13551321 - 2¹ = 13551319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (13551721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38655 + ... + 39003.

It is an arithmetic number, because the mean of its divisors is an integer number (883400).

Almost surely, 2^13551321 is an apocalyptic number.

It is an amenable number.

13551321 is a deficient number, since it is larger than the sum of its proper divisors (7650279).

13551321 is an equidigital number, since it uses as much as digits as its factorization.

13551321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445 (or 402 counting only the distinct ones).

The product of its digits is 450, while the sum is 21.

The square root of 13551321 is about 3681.2118928418. The cubic root of 13551321 is about 238.4115059177.

Adding to 13551321 its reverse (12315531), we get a palindrome (25866852).

The spelling of 13551321 in words is "thirteen million, five hundred fifty-one thousand, three hundred twenty-one".