57420021 has 8 divisors (see below), whose sum is σ = 76612864. Its totient is φ = 38253600.

The previous prime is 57420017. The next prime is 57420031. The reversal of 57420021 is 12002475.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 57420021 - 2² = 57420017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 57420021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57420031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 805 + ... + 10746.

It is an arithmetic number, because the mean of its divisors is an integer number (9576608).

Almost surely, 2^57420021 is an apocalyptic number.

It is an amenable number.

57420021 is a deficient number, since it is larger than the sum of its proper divisors (19192843).

57420021 is a wasteful number, since it uses less digits than its factorization.

57420021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13211.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 57420021 is about 7577.5999498522. The cubic root of 57420021 is about 385.7930938520.

Adding to 57420021 its reverse (12002475), we get a palindrome (69422496).

The spelling of 57420021 in words is "fifty-seven million, four hundred twenty thousand, twenty-one".