21238025 has 12 divisors (see below), whose sum is σ = 26402700. Its totient is φ = 16946880.

The previous prime is 21237973. The next prime is 21238033. The reversal of 21238025 is 52083212.

It can be written as a sum of positive squares in 6 ways, for example, as 41209 + 21196816 = 203^2 + 4604^2 .

It is not a de Polignac number, because 21238025 - 2¹⁸ = 20975881 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11891 + ... + 13559.

It is an arithmetic number, because the mean of its divisors is an integer number (2200225).

Almost surely, 2^21238025 is an apocalyptic number.

21238025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21238025 is a deficient number, since it is larger than the sum of its proper divisors (5164675).

21238025 is a wasteful number, since it uses less digits than its factorization.

21238025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188 (or 2183 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21238025 is about 4608.4731744907. The cubic root of 21238025 is about 276.9308737220.

The spelling of 21238025 in words is "twenty-one million, two hundred thirty-eight thousand, twenty-five".