52281221 has 4 divisors (see below), whose sum is σ = 53967744. Its totient is φ = 50594700.

The previous prime is 52281199. The next prime is 52281233. The reversal of 52281221 is 12218225.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-52281221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (52281241) 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, 843215 + ... + 843276.

It is an arithmetic number, because the mean of its divisors is an integer number (13491936).

Almost surely, 2^52281221 is an apocalyptic number.

It is an amenable number.

52281221 is a deficient number, since it is larger than the sum of its proper divisors (1686523).

52281221 is a wasteful number, since it uses less digits than its factorization.

52281221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1686522.

The product of its digits is 640, while the sum is 23.

The square root of 52281221 is about 7230.5754266172. The cubic root of 52281221 is about 373.9227656581.

Adding to 52281221 its reverse (12218225), we get a palindrome (64499446).

The spelling of 52281221 in words is "fifty-two million, two hundred eighty-one thousand, two hundred twenty-one".