57121321 has 4 divisors (see below), whose sum is σ = 57143044. Its totient is φ = 57099600.

The previous prime is 57121307. The next prime is 57121367. The reversal of 57121321 is 12312175.

It is a happy number.

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 30958096 + 26163225 = 5564^2 + 5115^2 .

It is a cyclic number.

It is not a de Polignac number, because 57121321 - 2⁵ = 57121289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 57121292 and 57121301.

It is not an unprimeable number, because it can be changed into a prime (57121301) 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, 6270 + ... + 12391.

It is an arithmetic number, because the mean of its divisors is an integer number (14285761).

Almost surely, 2^57121321 is an apocalyptic number.

It is an amenable number.

57121321 is a deficient number, since it is larger than the sum of its proper divisors (21723).

57121321 is a wasteful number, since it uses less digits than its factorization.

57121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21722.

The product of its digits is 420, while the sum is 22.

The square root of 57121321 is about 7557.8648439887. The cubic root of 57121321 is about 385.1229629160.

Adding to 57121321 its reverse (12312175), we get a palindrome (69433496).

The spelling of 57121321 in words is "fifty-seven million, one hundred twenty-one thousand, three hundred twenty-one".