217278825 has 12 divisors (see below), whose sum is σ = 359234448. Its totient is φ = 115882000.

The previous prime is 217278799. The next prime is 217278829. The reversal of 217278825 is 528872712.

It is not a de Polignac number, because 217278825 - 2¹¹ = 217276777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217278829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1448451 + ... + 1448600.

It is an arithmetic number, because the mean of its divisors is an integer number (29936204).

Almost surely, 2^217278825 is an apocalyptic number.

217278825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

217278825 is a deficient number, since it is larger than the sum of its proper divisors (141955623).

217278825 is a wasteful number, since it uses less digits than its factorization.

217278825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2897064 (or 2897059 counting only the distinct ones).

The product of its digits is 125440, while the sum is 42.

The square root of 217278825 is about 14740.3807617035. The cubic root of 217278825 is about 601.1817680678.

The spelling of 217278825 in words is "two hundred seventeen million, two hundred seventy-eight thousand, eight hundred twenty-five".