78866240 has 56 divisors (see below), whose sum is σ = 192904872. Its totient is φ = 30689280.

The previous prime is 78866231. The next prime is 78866261. The reversal of 78866240 is 4266887.

It can be written as a sum of positive squares in 4 ways, for example, as 42094144 + 36772096 = 6488^2 + 6064^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8510 + ... + 15170.

Almost surely, 2^78866240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78866240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96452436).

78866240 is an abundant number, since it is smaller than the sum of its proper divisors (114038632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78866240 is a wasteful number, since it uses less digits than its factorization.

78866240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6715 (or 6705 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 41.

The square root of 78866240 is about 8880.6666416435. Note that the first 4 decimals coincide. The cubic root of 78866240 is about 428.8417359317.

The spelling of 78866240 in words is "seventy-eight million, eight hundred sixty-six thousand, two hundred forty".