78805440 has 224 divisors, whose sum is σ = 317967360. Its totient is φ = 17998848.

The previous prime is 78805439. The next prime is 78805451. The reversal of 78805440 is 4450887.

It is a tau number, because it is divible by the number of its divisors (224).

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 = 78805395 and 78805404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59829 + ... + 61131.

Almost surely, 2^78805440 is an apocalyptic number.

78805440 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78805440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158983680).

78805440 is an abundant number, since it is smaller than the sum of its proper divisors (239161920).

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

78805440 is a wasteful number, since it uses less digits than its factorization.

78805440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336 (or 1320 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 78805440 is about 8877.2428151989. The cubic root of 78805440 is about 428.7315059157.

The spelling of 78805440 in words is "seventy-eight million, eight hundred five thousand, four hundred forty".