21200525 has 12 divisors (see below), whose sum is σ = 26849472. Its totient is φ = 16598640.

The previous prime is 21200521. The next prime is 21200533. The reversal of 21200525 is 52500212.

It is not a de Polignac number, because 21200525 - 2² = 21200521 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200521) 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, 7847 + ... + 10196.

It is an arithmetic number, because the mean of its divisors is an integer number (2237456).

Almost surely, 2^21200525 is an apocalyptic number.

21200525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21200525 is a deficient number, since it is larger than the sum of its proper divisors (5648947).

21200525 is a wasteful number, since it uses less digits than its factorization.

21200525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18100 (or 18095 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 21200525 is about 4604.4027842924. The cubic root of 21200525 is about 276.7677853309.

Adding to 21200525 its reverse (52500212), we get a palindrome (73700737).

The spelling of 21200525 in words is "twenty-one million, two hundred thousand, five hundred twenty-five".