21753825 has 24 divisors (see below), whose sum is σ = 36381600. Its totient is φ = 11468160.

The previous prime is 21753793. The next prime is 21753827. The reversal of 21753825 is 52835712.

It is not a de Polignac number, because 21753825 - 2⁵ = 21753793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21753827) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5046 + ... + 8304.

It is an arithmetic number, because the mean of its divisors is an integer number (1515900).

Almost surely, 2^21753825 is an apocalyptic number.

21753825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21753825 is a deficient number, since it is larger than the sum of its proper divisors (14627775).

21753825 is a wasteful number, since it uses less digits than its factorization.

21753825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3361 (or 3356 counting only the distinct ones).

The product of its digits is 16800, while the sum is 33.

The square root of 21753825 is about 4664.0995915611. The cubic root of 21753825 is about 279.1548709157.

It can be divided in two parts, 21753 and 825, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 21753825 in words is "twenty-one million, seven hundred fifty-three thousand, eight hundred twenty-five".