57215421 has 48 divisors (see below), whose sum is σ = 93000960. Its totient is φ = 33707520.

The previous prime is 57215407. The next prime is 57215423. The reversal of 57215421 is 12451275.

It is not a de Polignac number, because 57215421 - 2⁷ = 57215293 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57215423) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 249735 + ... + 249963.

It is an arithmetic number, because the mean of its divisors is an integer number (1937520).

Almost surely, 2^57215421 is an apocalyptic number.

57215421 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

57215421 is a deficient number, since it is larger than the sum of its proper divisors (35785539).

57215421 is a wasteful number, since it uses less digits than its factorization.

57215421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346 (or 343 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 57215421 is about 7564.0875854263. The cubic root of 57215421 is about 385.3343270097.

Adding to 57215421 its reverse (12451275), we get a palindrome (69666696).

The spelling of 57215421 in words is "fifty-seven million, two hundred fifteen thousand, four hundred twenty-one".