78991144 has 8 divisors (see below), whose sum is σ = 148108410.
Its totient is φ = 39495568.
The previous prime is 78991141. The next prime is 78991153. The reversal of 78991144 is 44119987.
It can be written as a sum of positive squares in only one way, i.e., 44063044 + 34928100 = 6638^2 + 5910^2
It is a tau number, because it is divible by the number of its divisors (8).
It is a self number, because there is not a number n which added to its sum of digits gives 78991144.
It is not an unprimeable number, because it can be changed into a prime (78991141) by changing a digit.
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 as a sum of consecutive naturals, namely, 4936939 + ... + 4936954.
Almost surely, 278991144 is an apocalyptic number.
It is an amenable number.
78991144 is a deficient number, since it is larger than the sum of its proper divisors (69117266).
78991144 is a wasteful number, since it uses less digits than its factorization.
78991144 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 9873899 (or 9873895 counting only the distinct ones).
The product of its digits is 72576, while the sum is 43.
The square root of 78991144 is about 8887.6962144304.
The cubic root of 78991144 is about 429.0680084820.
The spelling of 78991144 in words is "seventy-eight million, nine hundred ninety-one thousand, one hundred forty-four".