78311844 has 72 divisors (see below), whose sum is σ = 224427840. Its totient is φ = 22825152.

The previous prime is 78311839. The next prime is 78311851. The reversal of 78311844 is 44811387.

It is a super-2 number, since 2×78311844² = 12265489821360672, which contains 22 as substring.

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 = 78311799 and 78311808.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4489 + ... + 13295.

Almost surely, 2^78311844 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 78311844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112213920).

78311844 is an abundant number, since it is smaller than the sum of its proper divisors (146115996).

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

78311844 is a wasteful number, since it uses less digits than its factorization.

78311844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8849 (or 8844 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 78311844 is about 8849.3979456232. The cubic root of 78311844 is about 427.8345140067.

The spelling of 78311844 in words is "seventy-eight million, three hundred eleven thousand, eight hundred forty-four".