978890640 has 480 divisors, whose sum is σ = 4013493120. Its totient is φ = 195084288.

The previous prime is 978890623. The next prime is 978890669. The reversal of 978890640 is 46098879.

It is a happy number.

978890640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2904552 + ... + 2904888.

It is an arithmetic number, because the mean of its divisors is an integer number (8361444).

Almost surely, 2^978890640 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 978890640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2006746560).

978890640 is an abundant number, since it is smaller than the sum of its proper divisors (3034602480).

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

978890640 is a wasteful number, since it uses less digits than its factorization.

978890640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 51.

The square root of 978890640 is about 31287.2280651387. The cubic root of 978890640 is about 992.9134460469.

The spelling of 978890640 in words is "nine hundred seventy-eight million, eight hundred ninety thousand, six hundred forty".