79778440 has 64 divisors (see below), whose sum is σ = 208085760. Its totient is φ = 26960640.

The previous prime is 79778437. The next prime is 79778453. The reversal of 79778440 is 4487797.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17874 + ... + 21886.

It is an arithmetic number, because the mean of its divisors is an integer number (3251340).

Almost surely, 2^79778440 is an apocalyptic number.

79778440 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 79778440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104042880).

79778440 is an abundant number, since it is smaller than the sum of its proper divisors (128307320).

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

79778440 is a wasteful number, since it uses less digits than its factorization.

79778440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4102 (or 4098 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 46.

The square root of 79778440 is about 8931.8777421100. The cubic root of 79778440 is about 430.4887897644.

The spelling of 79778440 in words is "seventy-nine million, seven hundred seventy-eight thousand, four hundred forty".