78586440 has 64 divisors (see below), whose sum is σ = 237375360. Its totient is φ = 20812800.

The previous prime is 78586429. The next prime is 78586481. The reversal of 78586440 is 4468587.

It is a junction number, because it is equal to n+sod(n) for n = 78586392 and 78586401.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 15952 + ... + 20288.

It is an arithmetic number, because the mean of its divisors is an integer number (3708990).

Almost surely, 2^78586440 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 78586440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118687680).

78586440 is an abundant number, since it is smaller than the sum of its proper divisors (158788920).

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

78586440 is a wasteful number, since it uses less digits than its factorization.

78586440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4502 (or 4498 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The square root of 78586440 is about 8864.8993226094. The cubic root of 78586440 is about 428.3339897473. Note that the first 3 decimals are identical.

The spelling of 78586440 in words is "seventy-eight million, five hundred eighty-six thousand, four hundred forty".