78916881 has 4 divisors (see below), whose sum is σ = 105222512. Its totient is φ = 52611252.

The previous prime is 78916879. The next prime is 78916921. The reversal of 78916881 is 18861987.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18861987 = 3 ⋅6287329.

It is not a de Polignac number, because 78916881 - 2¹ = 78916879 is a prime.

It is a super-2 number, since 2×78916881² = 12455748213536322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78916881.

It is not an unprimeable number, because it can be changed into a prime (78916811) 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 3 ways as a sum of consecutive naturals, for example, 13152811 + ... + 13152816.

It is an arithmetic number, because the mean of its divisors is an integer number (26305628).

Almost surely, 2^78916881 is an apocalyptic number.

It is an amenable number.

78916881 is a deficient number, since it is larger than the sum of its proper divisors (26305631).

78916881 is a wasteful number, since it uses less digits than its factorization.

78916881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26305630.

The product of its digits is 193536, while the sum is 48.

The square root of 78916881 is about 8883.5173777057. The cubic root of 78916881 is about 428.9335045083.

It can be divided in two parts, 78916 and 881, that added together give a palindrome (79797).

The spelling of 78916881 in words is "seventy-eight million, nine hundred sixteen thousand, eight hundred eighty-one".