78447289 has 8 divisors (see below), whose sum is σ = 80898048. Its totient is φ = 76014000.

The previous prime is 78447283. The next prime is 78447293. The reversal of 78447289 is 98274487.

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 78447289 - 2²⁵ = 44892857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78447283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5064 + ... + 13510.

It is an arithmetic number, because the mean of its divisors is an integer number (10112256).

It is a vampire number, since it can be written as 8447 ⋅ 9287 (with its own digits).

Almost surely, 2^78447289 is an apocalyptic number.

It is an amenable number.

78447289 is a deficient number, since it is larger than the sum of its proper divisors (2450759).

78447289 is a wasteful number, since it uses less digits than its factorization.

78447289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8735.

The product of its digits is 903168, while the sum is 49.

The square root of 78447289 is about 8857.0474199927. The cubic root of 78447289 is about 428.0810270357.

The spelling of 78447289 in words is "seventy-eight million, four hundred forty-seven thousand, two hundred eighty-nine".