978221718432 has 192 divisors, whose sum is σ = 3286416752640. Its totient is φ = 277290978048.

The previous prime is 978221718431. The next prime is 978221718443. The reversal of 978221718432 is 234817122879.

978221718432 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (978221718431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131313 + ... + 1404879.

It is an arithmetic number, because the mean of its divisors is an integer number (17116753920).

Almost surely, 2^978221718432 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 978221718432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1643208376320).

978221718432 is an abundant number, since it is smaller than the sum of its proper divisors (2308195034208).

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

978221718432 is a wasteful number, since it uses less digits than its factorization.

978221718432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273720 (or 1273706 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The spelling of 978221718432 in words is "nine hundred seventy-eight billion, two hundred twenty-one million, seven hundred eighteen thousand, four hundred thirty-two".