78517620 has 96 divisors (see below), whose sum is σ = 246960000. Its totient is φ = 20708352.

The previous prime is 78517609. The next prime is 78517651. The reversal of 78517620 is 2671587.

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

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 51631 + ... + 53129.

It is an arithmetic number, because the mean of its divisors is an integer number (2572500).

Almost surely, 2^78517620 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 78517620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123480000).

78517620 is an abundant number, since it is smaller than the sum of its proper divisors (168442380).

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

78517620 is a wasteful number, since it uses less digits than its factorization.

78517620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 78517620 is about 8861.0168716688. The cubic root of 78517620 is about 428.2089191703.

The spelling of 78517620 in words is "seventy-eight million, five hundred seventeen thousand, six hundred twenty".