15342221 has 4 divisors (see below), whose sum is σ = 15352092. Its totient is φ = 15332352.

The previous prime is 15342209. The next prime is 15342233. The reversal of 15342221 is 12224351.

15342221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12224351 = 67 ⋅182453.

It is an interprime number because it is at equal distance from previous prime (15342209) and next prime (15342233).

It can be written as a sum of positive squares in 2 ways, for example, as 13586596 + 1755625 = 3686^2 + 1325^2 .

It is a cyclic number.

It is not a de Polignac number, because 15342221 - 2⁶ = 15342157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15342193 and 15342202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15342251) 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, 2036 + ... + 5901.

It is an arithmetic number, because the mean of its divisors is an integer number (3838023).

Almost surely, 2^15342221 is an apocalyptic number.

It is an amenable number.

15342221 is a deficient number, since it is larger than the sum of its proper divisors (9871).

15342221 is an equidigital number, since it uses as much as digits as its factorization.

15342221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9870.

The product of its digits is 480, while the sum is 20.

The square root of 15342221 is about 3916.9147297331. The cubic root of 15342221 is about 248.4826546170.

Adding to 15342221 its reverse (12224351), we get a palindrome (27566572).

It can be divided in two parts, 15 and 342221, that multiplied together give a palindrome (5133315).

The spelling of 15342221 in words is "fifteen million, three hundred forty-two thousand, two hundred twenty-one".