21567825 has 18 divisors (see below), whose sum is σ = 38630774. Its totient is φ = 11502720.

The previous prime is 21567823. The next prime is 21567827. The reversal of 21567825 is 52876512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21567823) and next prime (21567827).

It can be written as a sum of positive squares in 3 ways, for example, as 1089 + 21566736 = 33^2 + 4644^2 .

It is not a de Polignac number, because 21567825 - 2¹ = 21567823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21567825.

It is not an unprimeable number, because it can be changed into a prime (21567823) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 47704 + ... + 48153.

Almost surely, 2^21567825 is an apocalyptic number.

21567825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21567825 is a deficient number, since it is larger than the sum of its proper divisors (17062949).

21567825 is a wasteful number, since it uses less digits than its factorization.

21567825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95873 (or 95865 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 21567825 is about 4644.1172465820. The cubic root of 21567825 is about 278.3569806324.

The spelling of 21567825 in words is "twenty-one million, five hundred sixty-seven thousand, eight hundred twenty-five".