978783840 has 144 divisors (see below), whose sum is σ = 3536664768. Its totient is φ = 245649408.

The previous prime is 978783779. The next prime is 978783907. The reversal of 978783840 is 48387879.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4489 + ... + 44471.

It is an arithmetic number, because the mean of its divisors is an integer number (24560172).

Almost surely, 2^978783840 is an apocalyptic number.

978783840 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 978783840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1768332384).

978783840 is an abundant number, since it is smaller than the sum of its proper divisors (2557880928).

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

978783840 is a wasteful number, since it uses less digits than its factorization.

978783840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40021 (or 40010 counting only the distinct ones).

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

The square root of 978783840 is about 31285.5212518507. The cubic root of 978783840 is about 992.8773347564.

The spelling of 978783840 in words is "nine hundred seventy-eight million, seven hundred eighty-three thousand, eight hundred forty".