252120221 has 4 divisors (see below), whose sum is σ = 252173244. Its totient is φ = 252067200.

The previous prime is 252120203. The next prime is 252120233. The reversal of 252120221 is 122021252.

252120221 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 8916196 + 243204025 = 2986^2 + 15595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-252120221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 252120221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252150221) 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, 18590 + ... + 29151.

It is an arithmetic number, because the mean of its divisors is an integer number (63043311).

Almost surely, 2^252120221 is an apocalyptic number.

It is an amenable number.

252120221 is a deficient number, since it is larger than the sum of its proper divisors (53023).

252120221 is an equidigital number, since it uses as much as digits as its factorization.

252120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53022.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 252120221 is about 15878.2940204545. The cubic root of 252120221 is about 631.7363881180.

Adding to 252120221 its reverse (122021252), we get a palindrome (374141473).

The spelling of 252120221 in words is "two hundred fifty-two million, one hundred twenty thousand, two hundred twenty-one".