20912225 has 12 divisors (see below), whose sum is σ = 25998336. Its totient is φ = 16686480.

The previous prime is 20912209. The next prime is 20912273. The reversal of 20912225 is 52221902.

It is not a de Polignac number, because 20912225 - 2⁴ = 20912209 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20912225.

It is a congruent number.

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, 11744 + ... + 13406.

It is an arithmetic number, because the mean of its divisors is an integer number (2166528).

Almost surely, 2^20912225 is an apocalyptic number.

20912225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20912225 is a deficient number, since it is larger than the sum of its proper divisors (5086111).

20912225 is a wasteful number, since it uses less digits than its factorization.

20912225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2176 (or 2171 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 20912225 is about 4572.9886288947. The cubic root of 20912225 is about 275.5074926350.

The spelling of 20912225 in words is "twenty million, nine hundred twelve thousand, two hundred twenty-five".