978448137891840 has 5616 divisors, whose sum is σ = 4670270451834624. Its totient is φ = 192313613352960.

The previous prime is 978448137891817. The next prime is 978448137891841. The reversal of 978448137891840 is 48198731844879.

978448137891840 is a `hidden beast` number, since 9 + 7 + 8 + 4 + 4 + 81 + 378 + 91 + 84 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 978448137891840.

It is not an unprimeable number, because it can be changed into a prime (978448137891841) by changing a digit.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 1521692282559 + ... + 1521692283201.

Almost surely, 2^{978448137891840} is an apocalyptic number.

978448137891840 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 978448137891840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2335135225917312).

978448137891840 is an abundant number, since it is smaller than the sum of its proper divisors (3691822313942784).

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

978448137891840 is a wasteful number, since it uses less digits than its factorization.

978448137891840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754 (or 690 counting only the distinct ones).

The product of its (nonzero) digits is 3121348608, while the sum is 81.

The spelling of 978448137891840 in words is "nine hundred seventy-eight trillion, four hundred forty-eight billion, one hundred thirty-seven million, eight hundred ninety-one thousand, eight hundred forty".