15221121 has 8 divisors (see below), whose sum is σ = 20539680. Its totient is φ = 10024992.

The previous prime is 15221099. The next prime is 15221149. The reversal of 15221121 is 12112251.

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

It is not a de Polignac number, because 15221121 - 2⁹ = 15220609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15221121.

It is not an unprimeable number, because it can be changed into a prime (15221161) 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, 30316 + ... + 30813.

It is an arithmetic number, because the mean of its divisors is an integer number (2567460).

Almost surely, 2^15221121 is an apocalyptic number.

It is an amenable number.

15221121 is a deficient number, since it is larger than the sum of its proper divisors (5318559).

15221121 is an equidigital number, since it uses as much as digits as its factorization.

15221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61215.

The product of its digits is 40, while the sum is 15.

The square root of 15221121 is about 3901.4255087083. The cubic root of 15221121 is about 247.8271482404.

Adding to 15221121 its reverse (12112251), we get a palindrome (27333372).

The spelling of 15221121 in words is "fifteen million, two hundred twenty-one thousand, one hundred twenty-one".