57530821 has 4 divisors (see below), whose sum is σ = 57950892. Its totient is φ = 57110752.

The previous prime is 57530807. The next prime is 57530857. The reversal of 57530821 is 12803575.

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 26894596 + 30636225 = 5186^2 + 5535^2 .

It is a cyclic number.

It is not a de Polignac number, because 57530821 - 2¹⁹ = 57006533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57530321) 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, 209830 + ... + 210103.

It is an arithmetic number, because the mean of its divisors is an integer number (14487723).

Almost surely, 2^57530821 is an apocalyptic number.

It is an amenable number.

57530821 is a deficient number, since it is larger than the sum of its proper divisors (420071).

57530821 is a wasteful number, since it uses less digits than its factorization.

57530821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420070.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 57530821 is about 7584.9074483477. The cubic root of 57530821 is about 386.0410817417.

The spelling of 57530821 in words is "fifty-seven million, five hundred thirty thousand, eight hundred twenty-one".