78638611 has 2 divisors, whose sum is σ = 78638612. Its totient is φ = 78638610.

The previous prime is 78638569. The next prime is 78638627. The reversal of 78638611 is 11683687.

It is a strong prime.

It is an emirp because it is prime and its reverse (11683687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78638611 - 2¹⁵ = 78605843 is a prime.

It is a super-2 number, since 2×78638611² = 12368062280018642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78638011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39319305 + 39319306.

It is an arithmetic number, because the mean of its divisors is an integer number (39319306).

Almost surely, 2^78638611 is an apocalyptic number.

78638611 is a deficient number, since it is larger than the sum of its proper divisors (1).

78638611 is an equidigital number, since it uses as much as digits as its factorization.

78638611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 40.

The square root of 78638611 is about 8867.8413946123. The cubic root of 78638611 is about 428.4287544817.

The spelling of 78638611 in words is "seventy-eight million, six hundred thirty-eight thousand, six hundred eleven".