215325221 has 4 divisors (see below), whose sum is σ = 215441100. Its totient is φ = 215209344.

The previous prime is 215325217. The next prime is 215325223. The reversal of 215325221 is 122523512.

215325221 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.

It can be written as a sum of positive squares in 2 ways, for example, as 160934596 + 54390625 = 12686^2 + 7375^2 .

It is a cyclic number.

It is not a de Polignac number, because 215325221 - 2² = 215325217 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 (215325223) 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, 55106 + ... + 58883.

It is an arithmetic number, because the mean of its divisors is an integer number (53860275).

Almost surely, 2^215325221 is an apocalyptic number.

It is an amenable number.

215325221 is a deficient number, since it is larger than the sum of its proper divisors (115879).

215325221 is a wasteful number, since it uses less digits than its factorization.

215325221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115878.

The product of its digits is 1200, while the sum is 23.

The square root of 215325221 is about 14673.9640520208. The cubic root of 215325221 is about 599.3745528827.

Adding to 215325221 its reverse (122523512), we get a palindrome (337848733).

The spelling of 215325221 in words is "two hundred fifteen million, three hundred twenty-five thousand, two hundred twenty-one".