215649225 has 81 divisors (see below), whose sum is σ = 429381589. Its totient is φ = 103382400.

The previous prime is 215649193. The next prime is 215649253. The reversal of 215649225 is 522946512.

The square root of 215649225 is 14685.

It is a perfect power (a square), and thus also a powerful number.

215649225 is a `hidden beast` number, since 2 + 1 + 5 + 649 + 2 + 2 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 44876601 + 170772624 = 6699^2 + 13068^2 .

It is not a de Polignac number, because 215649225 - 2⁵ = 215649193 is a prime.

It is a Duffinian number.

Its product of digits (43200) is a multiple of the sum of its prime divisors (108).

It is a self number, because there is not a number n which added to its sum of digits gives 215649225.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2422981 + ... + 2423069.

Almost surely, 2^215649225 is an apocalyptic number.

215649225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

215649225 is the 14685-th square number.

215649225 is the 7343-rd centered octagonal number.

It is an amenable number.

215649225 is a deficient number, since it is larger than the sum of its proper divisors (213732364).

215649225 is a wasteful number, since it uses less digits than its factorization.

215649225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 108 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The cubic root of 215649225 is about 599.6750323585.

Multiplying 215649225 by its sum of digits (36), we get a square (7763372100 = 88110²).

The spelling of 215649225 in words is "two hundred fifteen million, six hundred forty-nine thousand, two hundred twenty-five".