52821221 has 2 divisors, whose sum is σ = 52821222. Its totient is φ = 52821220.

The previous prime is 52821211. The next prime is 52821229. The reversal of 52821221 is 12212825.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47128225 + 5692996 = 6865^2 + 2386^2 .

It is a cyclic number.

It is not a de Polignac number, because 52821221 - 2¹⁰ = 52820197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (52821229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26410610 + 26410611.

It is an arithmetic number, because the mean of its divisors is an integer number (26410611).

Almost surely, 2^52821221 is an apocalyptic number.

It is an amenable number.

52821221 is a deficient number, since it is larger than the sum of its proper divisors (1).

52821221 is an equidigital number, since it uses as much as digits as its factorization.

52821221 is an evil number, because the sum of its binary digits is even.

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

The square root of 52821221 is about 7267.8209251467. The cubic root of 52821221 is about 375.2057442826.

The spelling of 52821221 in words is "fifty-two million, eight hundred twenty-one thousand, two hundred twenty-one".