21825057 has 4 divisors (see below), whose sum is σ = 29100080. Its totient is φ = 14550036.

The previous prime is 21825043. The next prime is 21825071. The reversal of 21825057 is 75052812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21825043) and next prime (21825071).

It is not a de Polignac number, because 21825057 - 2⁸ = 21824801 is a prime.

It is a super-2 number, since 2×21825057² = 952666226106498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21825017) 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, 3637507 + ... + 3637512.

It is an arithmetic number, because the mean of its divisors is an integer number (7275020).

Almost surely, 2^21825057 is an apocalyptic number.

It is an amenable number.

21825057 is a deficient number, since it is larger than the sum of its proper divisors (7275023).

21825057 is an equidigital number, since it uses as much as digits as its factorization.

21825057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7275022.

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 21825057 is about 4671.7295512476. The cubic root of 21825057 is about 279.4592326424.

Adding to 21825057 its reverse (75052812), we get a palindrome (96877869).

The spelling of 21825057 in words is "twenty-one million, eight hundred twenty-five thousand, fifty-seven".