78991104 has 72 divisors (see below), whose sum is σ = 211856512. Its totient is φ = 26127360.

The previous prime is 78991103. The next prime is 78991111. The reversal of 78991104 is 40119987.

It is a happy number.

It is a super-2 number, since 2×78991104² = 12479189022277632, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78991103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124869 + ... + 125499.

Almost surely, 2^78991104 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 78991104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105928256).

78991104 is an abundant number, since it is smaller than the sum of its proper divisors (132865408).

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

78991104 is a wasteful number, since it uses less digits than its factorization.

78991104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813 (or 799 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 78991104 is about 8887.6939641282. The cubic root of 78991104 is about 429.0679360573.

The spelling of 78991104 in words is "seventy-eight million, nine hundred ninety-one thousand, one hundred four".