21524025 has 12 divisors (see below), whose sum is σ = 35586512. Its totient is φ = 11479440.

The previous prime is 21523991. The next prime is 21524029. The reversal of 21524025 is 52042512.

It is a happy number.

It is not a de Polignac number, because 21524025 - 2⁶ = 21523961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21523992 and 21524010.

It is not an unprimeable number, because it can be changed into a prime (21524029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143419 + ... + 143568.

Almost surely, 2^21524025 is an apocalyptic number.

21524025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21524025 is a deficient number, since it is larger than the sum of its proper divisors (14062487).

21524025 is a wasteful number, since it uses less digits than its factorization.

21524025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287000 (or 286995 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21524025 is about 4639.3992067939. The cubic root of 21524025 is about 278.1684235528.

Adding to 21524025 its reverse (52042512), we get a palindrome (73566537).

The spelling of 21524025 in words is "twenty-one million, five hundred twenty-four thousand, twenty-five".