78398851 has 2 divisors, whose sum is σ = 78398852. Its totient is φ = 78398850.

The previous prime is 78398843. The next prime is 78398869. The reversal of 78398851 is 15889387.

It is a weak prime.

It is an emirp because it is prime and its reverse (15889387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78398851 - 2³ = 78398843 is a prime.

It is a super-2 number, since 2×78398851² = 12292759676240402, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78398795 and 78398804.

It is not a weakly prime, because it can be changed into another prime (78398821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199425 + 39199426.

It is an arithmetic number, because the mean of its divisors is an integer number (39199426).

Almost surely, 2^78398851 is an apocalyptic number.

78398851 is a deficient number, since it is larger than the sum of its proper divisors (1).

78398851 is an equidigital number, since it uses as much as digits as its factorization.

78398851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 49.

The square root of 78398851 is about 8854.3125650725. The cubic root of 78398851 is about 427.9929013729.

The spelling of 78398851 in words is "seventy-eight million, three hundred ninety-eight thousand, eight hundred fifty-one".