978391218 has 128 divisors (see below), whose sum is σ = 2368880640. Its totient is φ = 263672640.

The previous prime is 978391213. The next prime is 978391229. The reversal of 978391218 is 812193879.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (978391213) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11787805 + ... + 11787887.

It is an arithmetic number, because the mean of its divisors is an integer number (18506880).

Almost surely, 2^978391218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 978391218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184440320).

978391218 is an abundant number, since it is smaller than the sum of its proper divisors (1390489422).

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

978391218 is a wasteful number, since it uses less digits than its factorization.

978391218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292.

The product of its digits is 217728, while the sum is 48.

The square root of 978391218 is about 31279.2458029282. The cubic root of 978391218 is about 992.7445585483.

The spelling of 978391218 in words is "nine hundred seventy-eight million, three hundred ninety-one thousand, two hundred eighteen".