78928440 has 64 divisors (see below), whose sum is σ = 238563360. Its totient is φ = 20889600.

The previous prime is 78928427. The next prime is 78928441. The reversal of 78928440 is 4482987.

It is a junction number, because it is equal to n+sod(n) for n = 78928392 and 78928401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78928441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14040 + ... + 18840.

Almost surely, 2^78928440 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 78928440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119281680).

78928440 is an abundant number, since it is smaller than the sum of its proper divisors (159634920).

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

78928440 is a wasteful number, since it uses less digits than its factorization.

78928440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4952 (or 4948 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 78928440 is about 8884.1679407809. The cubic root of 78928440 is about 428.9544455299.

The spelling of 78928440 in words is "seventy-eight million, nine hundred twenty-eight thousand, four hundred forty".