78182217 has 12 divisors (see below), whose sum is σ = 116573184. Its totient is φ = 50439960.

The previous prime is 78182149. The next prime is 78182243. The reversal of 78182217 is 71228187.

It is a happy number.

It is not a de Polignac number, because 78182217 - 2²³ = 69793609 is a prime.

It is a super-2 number, since 2×78182217² = 12224918110070178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78182417) 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, 139833 + ... + 140390.

It is an arithmetic number, because the mean of its divisors is an integer number (9714432).

Almost surely, 2^78182217 is an apocalyptic number.

It is an amenable number.

78182217 is a deficient number, since it is larger than the sum of its proper divisors (38390967).

78182217 is a wasteful number, since it uses less digits than its factorization.

78182217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280260 (or 280257 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 78182217 is about 8842.0708547263. The cubic root of 78182217 is about 427.5983235420.

The spelling of 78182217 in words is "seventy-eight million, one hundred eighty-two thousand, two hundred seventeen".