78387220840 has 64 divisors (see below), whose sum is σ = 179137344960. Its totient is φ = 30863838720.

The previous prime is 78387220829. The next prime is 78387220841. The reversal of 78387220840 is 4802278387.

It is a super-2 number, since 2×78387220840² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78387220841) 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 15 ways as a sum of consecutive naturals, for example, 3830235 + ... + 3850645.

It is an arithmetic number, because the mean of its divisors is an integer number (2799021015).

Almost surely, 2^78387220840 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 78387220840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89568672480).

78387220840 is an abundant number, since it is smaller than the sum of its proper divisors (100750124120).

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

78387220840 is a wasteful number, since it uses less digits than its factorization.

78387220840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21922 (or 21918 counting only the distinct ones).

The product of its (nonzero) digits is 1204224, while the sum is 49.

The spelling of 78387220840 in words is "seventy-eight billion, three hundred eighty-seven million, two hundred twenty thousand, eight hundred forty".