78281191 has 2 divisors, whose sum is σ = 78281192. Its totient is φ = 78281190.

The previous prime is 78281183. The next prime is 78281207. The reversal of 78281191 is 19118287.

It is a weak prime.

It is an emirp because it is prime and its reverse (19118287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78281191 - 2³ = 78281183 is a prime.

It is a super-2 number, since 2×78281191² = 12255889728756962, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78281191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78281101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39140595 + 39140596.

It is an arithmetic number, because the mean of its divisors is an integer number (39140596).

Almost surely, 2^78281191 is an apocalyptic number.

78281191 is a deficient number, since it is larger than the sum of its proper divisors (1).

78281191 is an equidigital number, since it uses as much as digits as its factorization.

78281191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 37.

The square root of 78281191 is about 8847.6658503811. The cubic root of 78281191 is about 427.7786854025.

The spelling of 78281191 in words is "seventy-eight million, two hundred eighty-one thousand, one hundred ninety-one".