252421221 has 16 divisors (see below), whose sum is σ = 362759936. Its totient is φ = 155203776.

The previous prime is 252421217. The next prime is 252421271. The reversal of 252421221 is 122124252.

252421221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 252421221 - 2² = 252421217 is a prime.

It is a super-2 number, since 2×252421221² = 127432945622261682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252421271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64116 + ... + 67938.

It is an arithmetic number, because the mean of its divisors is an integer number (22672496).

Almost surely, 2^252421221 is an apocalyptic number.

It is an amenable number.

252421221 is a deficient number, since it is larger than the sum of its proper divisors (110338715).

252421221 is a wasteful number, since it uses less digits than its factorization.

252421221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5532.

The product of its digits is 640, while the sum is 21.

The square root of 252421221 is about 15887.7695413799. The cubic root of 252421221 is about 631.9876928718.

Adding to 252421221 its reverse (122124252), we get a palindrome (374545473).

The spelling of 252421221 in words is "two hundred fifty-two million, four hundred twenty-one thousand, two hundred twenty-one".