57212321 has 2 divisors, whose sum is σ = 57212322. Its totient is φ = 57212320.

The previous prime is 57212299. The next prime is 57212347. The reversal of 57212321 is 12321275.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55294096 + 1918225 = 7436^2 + 1385^2 .

It is a cyclic number.

It is not a de Polignac number, because 57212321 - 2⁶ = 57212257 is a prime.

It is not a weakly prime, because it can be changed into another prime (57212521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28606160 + 28606161.

It is an arithmetic number, because the mean of its divisors is an integer number (28606161).

Almost surely, 2^57212321 is an apocalyptic number.

It is an amenable number.

57212321 is a deficient number, since it is larger than the sum of its proper divisors (1).

57212321 is an equidigital number, since it uses as much as digits as its factorization.

57212321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 57212321 is about 7563.8826669905. The cubic root of 57212321 is about 385.3273675923.

Adding to 57212321 its reverse (12321275), we get a palindrome (69533596).

The spelling of 57212321 in words is "fifty-seven million, two hundred twelve thousand, three hundred twenty-one".