57210221 has 4 divisors (see below), whose sum is σ = 59055744. Its totient is φ = 55364700.

The previous prime is 57210199. The next prime is 57210227. The reversal of 57210221 is 12201275.

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 not a de Polignac number, because 57210221 - 2¹⁸ = 56948077 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 57210193 and 57210202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57210227) 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, 922715 + ... + 922776.

It is an arithmetic number, because the mean of its divisors is an integer number (14763936).

Almost surely, 2^57210221 is an apocalyptic number.

It is an amenable number.

57210221 is a deficient number, since it is larger than the sum of its proper divisors (1845523).

57210221 is a wasteful number, since it uses less digits than its factorization.

57210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1845522.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 57210221 is about 7563.7438481218. The cubic root of 57210221 is about 385.3226530054.

Adding to 57210221 its reverse (12201275), we get a palindrome (69411496).

The spelling of 57210221 in words is "fifty-seven million, two hundred ten thousand, two hundred twenty-one".