978391440 has 160 divisors (see below), whose sum is σ = 3629351040. Its totient is φ = 240827904.

The previous prime is 978391399. The next prime is 978391451. The reversal of 978391440 is 44193879.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10659 + ... + 45501.

It is an arithmetic number, because the mean of its divisors is an integer number (22683444).

Almost surely, 2^978391440 is an apocalyptic number.

978391440 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 978391440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1814675520).

978391440 is an abundant number, since it is smaller than the sum of its proper divisors (2650959600).

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

978391440 is a wasteful number, since it uses less digits than its factorization.

978391440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34878 (or 34866 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 978391440 is about 31279.2493516069. The cubic root of 978391440 is about 992.7446336339.

The spelling of 978391440 in words is "nine hundred seventy-eight million, three hundred ninety-one thousand, four hundred forty".