21433525 has 6 divisors (see below), whose sum is σ = 26577602. Its totient is φ = 17146800.

The previous prime is 21433519. The next prime is 21433541. The reversal of 21433525 is 52533412.

It can be written as a sum of positive squares in 3 ways, for example, as 4186116 + 17247409 = 2046^2 + 4153^2 .

It is not a de Polignac number, because 21433525 - 2¹³ = 21425333 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 857341 = 21433525 / (2 + 1 + 4 + 3 + 3 + 5 + 2 + 5).

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 21433525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 428646 + ... + 428695.

Almost surely, 2^21433525 is an apocalyptic number.

21433525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21433525 is a deficient number, since it is larger than the sum of its proper divisors (5144077).

21433525 is an equidigital number, since it uses as much as digits as its factorization.

21433525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 857351 (or 857346 counting only the distinct ones).

The product of its digits is 3600, while the sum is 25.

The square root of 21433525 is about 4629.6355148111. The cubic root of 21433525 is about 277.7780131850.

Adding to 21433525 its reverse (52533412), we get a palindrome (73966937).

The spelling of 21433525 in words is "twenty-one million, four hundred thirty-three thousand, five hundred twenty-five".