21200725 has 24 divisors (see below), whose sum is σ = 32359040. Its totient is φ = 13417920.

The previous prime is 21200719. The next prime is 21200747. The reversal of 21200725 is 52700212.

It is not a de Polignac number, because 21200725 - 2²³ = 12812117 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2385 + ... + 6934.

Almost surely, 2^21200725 is an apocalyptic number.

21200725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21200725 is a deficient number, since it is larger than the sum of its proper divisors (11158315).

21200725 is a wasteful number, since it uses less digits than its factorization.

21200725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9349 (or 9344 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 21200725 is about 4604.4245025844. The cubic root of 21200725 is about 276.7686556456.

Adding to 21200725 its reverse (52700212), we get a palindrome (73900937).

The spelling of 21200725 in words is "twenty-one million, two hundred thousand, seven hundred twenty-five".