78268517 has 4 divisors (see below), whose sum is σ = 81671520. Its totient is φ = 74865516.

The previous prime is 78268513. The next prime is 78268523. The reversal of 78268517 is 71586287.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71586287 = 41 ⋅1746007.

It is a cyclic number.

It is not a de Polignac number, because 78268517 - 2² = 78268513 is a prime.

It is a super-2 number, since 2×78268517² = 12251921506758578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78268513) 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 3 ways as a sum of consecutive naturals, for example, 1701467 + ... + 1701512.

It is an arithmetic number, because the mean of its divisors is an integer number (20417880).

Almost surely, 2^78268517 is an apocalyptic number.

It is an amenable number.

78268517 is a deficient number, since it is larger than the sum of its proper divisors (3403003).

78268517 is a wasteful number, since it uses less digits than its factorization.

78268517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3403002.

The product of its digits is 188160, while the sum is 44.

The square root of 78268517 is about 8846.9495872871. The cubic root of 78268517 is about 427.7555978655.

The spelling of 78268517 in words is "seventy-eight million, two hundred sixty-eight thousand, five hundred seventeen".