79840440 has 96 divisors (see below), whose sum is σ = 260891280. Its totient is φ = 21175296.

The previous prime is 79840427. The next prime is 79840441. The reversal of 79840440 is 4404897.

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 = 79840395 and 79840404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79840441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81232 + ... + 82208.

Almost surely, 2^79840440 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 79840440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130445640).

79840440 is an abundant number, since it is smaller than the sum of its proper divisors (181050840).

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

79840440 is a wasteful number, since it uses less digits than its factorization.

79840440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221 (or 1214 counting only the distinct ones).

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

The square root of 79840440 is about 8935.3477828230. The cubic root of 79840440 is about 430.6002793423.

The spelling of 79840440 in words is "seventy-nine million, eight hundred forty thousand, four hundred forty".