78911988 has 72 divisors (see below), whose sum is σ = 199186176. Its totient is φ = 24288000.

The previous prime is 78911981. The next prime is 78911993. The reversal of 78911988 is 88911987.

It is a super-2 number, since 2×78911988² = 12454203700224288, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78911988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78911981) 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 in 23 ways as a sum of consecutive naturals, for example, 196588 + ... + 196988.

Almost surely, 2^78911988 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 78911988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99593088).

78911988 is an abundant number, since it is smaller than the sum of its proper divisors (120274188).

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

78911988 is a wasteful number, since it uses less digits than its factorization.

78911988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485 (or 460 counting only the distinct ones).

The product of its digits is 290304, while the sum is 51.

The square root of 78911988 is about 8883.2419757654. The cubic root of 78911988 is about 428.9246394214.

Subtracting 78911988 from its reverse (88911987), we obtain a palindrome (9999999).

The spelling of 78911988 in words is "seventy-eight million, nine hundred eleven thousand, nine hundred eighty-eight".