78019920 has 120 divisors (see below), whose sum is σ = 285865632. Its totient is φ = 18912000.

The previous prime is 78019891. The next prime is 78019927. The reversal of 78019920 is 2991087.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78019927) 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, 2995 + ... + 12845.

Almost surely, 2^78019920 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 78019920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142932816).

78019920 is an abundant number, since it is smaller than the sum of its proper divisors (207845712).

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

78019920 is a wasteful number, since it uses less digits than its factorization.

78019920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9881 (or 9872 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 78019920 is about 8832.8885422607. Note that the first 3 decimals coincide. The cubic root of 78019920 is about 427.3022374504.

The spelling of 78019920 in words is "seventy-eight million, nineteen thousand, nine hundred twenty".