78917225 has 12 divisors (see below), whose sum is σ = 99463500. Its totient is φ = 62097600.

The previous prime is 78917221. The next prime is 78917233. The reversal of 78917225 is 52271987.

It can be written as a sum of positive squares in 6 ways, for example, as 8826841 + 70090384 = 2971^2 + 8372^2 .

It is not a de Polignac number, because 78917225 - 2² = 78917221 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78917221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24350 + ... + 27399.

It is an arithmetic number, because the mean of its divisors is an integer number (8288625).

Almost surely, 2^78917225 is an apocalyptic number.

It is an amenable number.

78917225 is a deficient number, since it is larger than the sum of its proper divisors (20546275).

78917225 is a wasteful number, since it uses less digits than its factorization.

78917225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51820 (or 51815 counting only the distinct ones).

The product of its digits is 70560, while the sum is 41.

The square root of 78917225 is about 8883.5367393848. The cubic root of 78917225 is about 428.9341277501.

The spelling of 78917225 in words is "seventy-eight million, nine hundred seventeen thousand, two hundred twenty-five".