21536225 has 12 divisors (see below), whose sum is σ = 26831616. Its totient is φ = 17147280.

The previous prime is 21536213. The next prime is 21536261. The reversal of 21536225 is 52263512.

It is not a de Polignac number, because 21536225 - 2²⁴ = 4759009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21536194 and 21536203.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3644 + ... + 7506.

It is an arithmetic number, because the mean of its divisors is an integer number (2235968).

Almost surely, 2^21536225 is an apocalyptic number.

21536225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21536225 is a deficient number, since it is larger than the sum of its proper divisors (5295391).

21536225 is a wasteful number, since it uses less digits than its factorization.

21536225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4096 (or 4091 counting only the distinct ones).

The product of its digits is 3600, while the sum is 26.

The square root of 21536225 is about 4640.7138459509. The cubic root of 21536225 is about 278.2209697004.

Adding to 21536225 its reverse (52263512), we get a palindrome (73799737).

The spelling of 21536225 in words is "twenty-one million, five hundred thirty-six thousand, two hundred twenty-five".