57242021 has 2 divisors, whose sum is σ = 57242022. Its totient is φ = 57242020.

The previous prime is 57241999. The next prime is 57242033. The reversal of 57242021 is 12024275.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46444225 + 10797796 = 6815^2 + 3286^2 .

It is a cyclic number.

It is not a de Polignac number, because 57242021 - 2⁶ = 57241957 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57242051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28621010 + 28621011.

It is an arithmetic number, because the mean of its divisors is an integer number (28621011).

Almost surely, 2^57242021 is an apocalyptic number.

It is an amenable number.

57242021 is a deficient number, since it is larger than the sum of its proper divisors (1).

57242021 is an equidigital number, since it uses as much as digits as its factorization.

57242021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 57242021 is about 7565.8456896767. The cubic root of 57242021 is about 385.3940329707.

Adding to 57242021 its reverse (12024275), we get a palindrome (69266296).

The spelling of 57242021 in words is "fifty-seven million, two hundred forty-two thousand, twenty-one".