15222121 has 4 divisors (see below), whose sum is σ = 15230032. Its totient is φ = 15214212.

The previous prime is 15222101. The next prime is 15222131. The reversal of 15222121 is 12122251.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12122251 = 2857 ⋅4243.

It is a cyclic number.

It is not a de Polignac number, because 15222121 - 2¹⁹ = 14697833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15222095 and 15222104.

It is not an unprimeable number, because it can be changed into a prime (15222101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1006 + ... + 5608.

It is an arithmetic number, because the mean of its divisors is an integer number (3807508).

Almost surely, 2^15222121 is an apocalyptic number.

It is an amenable number.

15222121 is a deficient number, since it is larger than the sum of its proper divisors (7911).

15222121 is an equidigital number, since it uses as much as digits as its factorization.

15222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7910.

The product of its digits is 80, while the sum is 16.

The square root of 15222121 is about 3901.5536648879. The cubic root of 15222121 is about 247.8325753860.

Adding to 15222121 its reverse (12122251), we get a palindrome (27344372).

The spelling of 15222121 in words is "fifteen million, two hundred twenty-two thousand, one hundred twenty-one".