13161221 has 8 divisors (see below), whose sum is σ = 13777344. Its totient is φ = 12548800.

The previous prime is 13161193. The next prime is 13161229. The reversal of 13161221 is 12216131.

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

It is not a de Polignac number, because 13161221 - 2¹⁸ = 12899077 is a prime.

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 13161221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13161229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8510 + ... + 9936.

It is an arithmetic number, because the mean of its divisors is an integer number (1722168).

Almost surely, 2^13161221 is an apocalyptic number.

It is an amenable number.

13161221 is a deficient number, since it is larger than the sum of its proper divisors (616123).

13161221 is a wasteful number, since it uses less digits than its factorization.

13161221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1851.

The product of its digits is 72, while the sum is 17.

The square root of 13161221 is about 3627.8397153127. The cubic root of 13161221 is about 236.1014896728.

Adding to 13161221 its reverse (12216131), we get a palindrome (25377352).

The spelling of 13161221 in words is "thirteen million, one hundred sixty-one thousand, two hundred twenty-one".