21252425 has 12 divisors (see below), whose sum is σ = 26434320. Its totient is φ = 16949520.

The previous prime is 21252403. The next prime is 21252433. The reversal of 21252425 is 52425212.

It is not a de Polignac number, because 21252425 - 2¹⁰ = 21251401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21252425.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8354 + ... + 10596.

It is an arithmetic number, because the mean of its divisors is an integer number (2202860).

Almost surely, 2^21252425 is an apocalyptic number.

21252425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21252425 is a deficient number, since it is larger than the sum of its proper divisors (5181895).

21252425 is a wasteful number, since it uses less digits than its factorization.

21252425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2632 (or 2627 counting only the distinct ones).

The product of its digits is 1600, while the sum is 23.

The square root of 21252425 is about 4610.0352493229. The cubic root of 21252425 is about 276.9934486497.

Adding to 21252425 its reverse (52425212), we get a palindrome (73677637).

The spelling of 21252425 in words is "twenty-one million, two hundred fifty-two thousand, four hundred twenty-five".