78338817 has 6 divisors (see below), whose sum is σ = 113156082. Its totient is φ = 52225872.

The previous prime is 78338753. The next prime is 78338833. The reversal of 78338817 is 71883387.

It can be written as a sum of positive squares in only one way, i.e., 62346816 + 15992001 = 7896^2 + 3999^2 .

It is not a de Polignac number, because 78338817 - 2⁶ = 78338753 is a prime.

It is a super-2 number, since 2×78338817² = 12273940497918978, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78338837) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4352148 + ... + 4352165.

It is an arithmetic number, because the mean of its divisors is an integer number (18859347).

Almost surely, 2^78338817 is an apocalyptic number.

It is an amenable number.

78338817 is a deficient number, since it is larger than the sum of its proper divisors (34817265).

78338817 is a wasteful number, since it uses less digits than its factorization.

78338817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8704319 (or 8704316 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 78338817 is about 8850.9218163986. The cubic root of 78338817 is about 427.8836281428.

The spelling of 78338817 in words is "seventy-eight million, three hundred thirty-eight thousand, eight hundred seventeen".