78886217 has 2 divisors, whose sum is σ = 78886218. Its totient is φ = 78886216.

The previous prime is 78886211. The next prime is 78886219. The reversal of 78886217 is 71268887.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45373696 + 33512521 = 6736^2 + 5789^2 .

It is a cyclic number.

It is not a de Polignac number, because 78886217 - 2⁴ = 78886201 is a prime.

Together with 78886219, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78886211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39443108 + 39443109.

It is an arithmetic number, because the mean of its divisors is an integer number (39443109).

Almost surely, 2^78886217 is an apocalyptic number.

It is an amenable number.

78886217 is a deficient number, since it is larger than the sum of its proper divisors (1).

78886217 is an equidigital number, since it uses as much as digits as its factorization.

78886217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 301056, while the sum is 47.

The square root of 78886217 is about 8881.7913170711. The cubic root of 78886217 is about 428.8779417409.

The spelling of 78886217 in words is "seventy-eight million, eight hundred eighty-six thousand, two hundred seventeen".