57021257 has 4 divisors (see below), whose sum is σ = 57404100. Its totient is φ = 56638416.

The previous prime is 57021241. The next prime is 57021277. The reversal of 57021257 is 75212075.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5812921 + 51208336 = 2411^2 + 7156^2 .

It is a cyclic number.

It is not a de Polignac number, because 57021257 - 2⁴ = 57021241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (57021227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191198 + ... + 191495.

It is an arithmetic number, because the mean of its divisors is an integer number (14351025).

Almost surely, 2^57021257 is an apocalyptic number.

It is an amenable number.

57021257 is a deficient number, since it is larger than the sum of its proper divisors (382843).

57021257 is a wasteful number, since it uses less digits than its factorization.

57021257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382842.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 57021257 is about 7551.2420832602. The cubic root of 57021257 is about 384.8979478769.

The spelling of 57021257 in words is "fifty-seven million, twenty-one thousand, two hundred fifty-seven".