13501312221 has 4 divisors (see below), whose sum is σ = 18001749632. Its totient is φ = 9000874812.

The previous prime is 13501312219. The next prime is 13501312249. The reversal of 13501312221 is 12221310531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 13501312221 - 2¹ = 13501312219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13501312291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2250218701 + ... + 2250218706.

It is an arithmetic number, because the mean of its divisors is an integer number (4500437408).

Almost surely, 2^13501312221 is an apocalyptic number.

It is an amenable number.

13501312221 is a deficient number, since it is larger than the sum of its proper divisors (4500437411).

13501312221 is an equidigital number, since it uses as much as digits as its factorization.

13501312221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4500437410.

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 13501312221 its reverse (12221310531), we get a palindrome (25722622752).

The spelling of 13501312221 in words is "thirteen billion, five hundred one million, three hundred twelve thousand, two hundred twenty-one".