21936225 has 12 divisors (see below), whose sum is σ = 36268016. Its totient is φ = 11699280.

The previous prime is 21936217. The next prime is 21936247. The reversal of 21936225 is 52263912.

It is not a de Polignac number, because 21936225 - 2³ = 21936217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21936192 and 21936201.

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, 146167 + ... + 146316.

Almost surely, 2^21936225 is an apocalyptic number.

21936225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21936225 is a deficient number, since it is larger than the sum of its proper divisors (14331791).

21936225 is a wasteful number, since it uses less digits than its factorization.

21936225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292496 (or 292491 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 21936225 is about 4683.6123878904. The cubic root of 21936225 is about 279.9329133494.

The spelling of 21936225 in words is "twenty-one million, nine hundred thirty-six thousand, two hundred twenty-five".