57490021 has 2 divisors, whose sum is σ = 57490022. Its totient is φ = 57490020.

The previous prime is 57490019. The next prime is 57490031. The reversal of 57490021 is 12009475.

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., 50253921 + 7236100 = 7089^2 + 2690^2 .

It is a cyclic number.

It is not a de Polignac number, because 57490021 - 2¹ = 57490019 is a prime.

Together with 57490019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57490031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28745010 + 28745011.

It is an arithmetic number, because the mean of its divisors is an integer number (28745011).

Almost surely, 2^57490021 is an apocalyptic number.

It is an amenable number.

57490021 is a deficient number, since it is larger than the sum of its proper divisors (1).

57490021 is an equidigital number, since it uses as much as digits as its factorization.

57490021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 57490021 is about 7582.2174197262. The cubic root of 57490021 is about 385.9498019682.

Adding to 57490021 its reverse (12009475), we get a palindrome (69499496).

The spelling of 57490021 in words is "fifty-seven million, four hundred ninety thousand, twenty-one".