21525265 has 16 divisors (see below), whose sum is σ = 26516160. Its totient is φ = 16768960.

The previous prime is 21525227. The next prime is 21525277. The reversal of 21525265 is 56252512.

It is not a de Polignac number, because 21525265 - 2⁹ = 21524753 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38367 + ... + 38923.

It is an arithmetic number, because the mean of its divisors is an integer number (1657260).

Almost surely, 2^21525265 is an apocalyptic number.

It is an amenable number.

21525265 is a deficient number, since it is larger than the sum of its proper divisors (4990895).

21525265 is a wasteful number, since it uses less digits than its factorization.

21525265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752.

The product of its digits is 6000, while the sum is 28.

The square root of 21525265 is about 4639.5328428625. The cubic root of 21525265 is about 278.1737652152.

Adding to 21525265 its reverse (56252512), we get a palindrome (77777777).

The spelling of 21525265 in words is "twenty-one million, five hundred twenty-five thousand, two hundred sixty-five".