78989820 has 384 divisors, whose sum is σ = 308883456. Its totient is φ = 14598144.

The previous prime is 78989819. The next prime is 78989863. The reversal of 78989820 is 2898987.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2134842 + ... + 2134878.

It is an arithmetic number, because the mean of its divisors is an integer number (804384).

Almost surely, 2^78989820 is an apocalyptic number.

78989820 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78989820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154441728).

78989820 is an abundant number, since it is smaller than the sum of its proper divisors (229893636).

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

78989820 is a wasteful number, since it uses less digits than its factorization.

78989820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 51.

The square root of 78989820 is about 8887.6217291242. The cubic root of 78989820 is about 429.0656112124.

It can be divided in two parts, 789 and 89820, that added together give a palindrome (90609).

The spelling of 78989820 in words is "seventy-eight million, nine hundred eighty-nine thousand, eight hundred twenty".