78940440 has 128 divisors (see below), whose sum is σ = 277056000. Its totient is φ = 19937664.

The previous prime is 78940429. The next prime is 78940441. The reversal of 78940440 is 4404987.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78940395 and 78940404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78940441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18597 + ... + 22443.

It is an arithmetic number, because the mean of its divisors is an integer number (2164500).

Almost surely, 2^78940440 is an apocalyptic number.

78940440 is the 5130-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78940440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138528000).

78940440 is an abundant number, since it is smaller than the sum of its proper divisors (198115560).

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

78940440 is a wasteful number, since it uses less digits than its factorization.

78940440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886 (or 3876 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78940440 is about 8884.8432738006. The cubic root of 78940440 is about 428.9761833323.

The spelling of 78940440 in words is "seventy-eight million, nine hundred forty thousand, four hundred forty".