78398281 has 8 divisors (see below), whose sum is σ = 87340680. Its totient is φ = 69871872.

The previous prime is 78398267. The next prime is 78398297. The reversal of 78398281 is 18289387.

It can be written as a sum of positive squares in 4 ways, for example, as 341056 + 78057225 = 584^2 + 8835^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78398281 - 2⁵ = 78398249 is a prime.

It is a super-2 number, since 2×78398281² = 12292580927509922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78398251) 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 in 7 ways as a sum of consecutive naturals, for example, 103600 + ... + 104353.

It is an arithmetic number, because the mean of its divisors is an integer number (10917585).

Almost surely, 2^78398281 is an apocalyptic number.

It is an amenable number.

78398281 is a deficient number, since it is larger than the sum of its proper divisors (8942399).

78398281 is a wasteful number, since it uses less digits than its factorization.

78398281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207995.

The product of its digits is 193536, while the sum is 46.

The square root of 78398281 is about 8854.2803773090. The cubic root of 78398281 is about 427.9918641275.

The spelling of 78398281 in words is "seventy-eight million, three hundred ninety-eight thousand, two hundred eighty-one".