9978238578 has 96 divisors (see below), whose sum is σ = 25703647488. Its totient is φ = 2553012000.

The previous prime is 9978238577. The next prime is 9978238579. The reversal of 9978238578 is 8758328799.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (9978238577) and next prime (9978238579).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is not an unprimeable number, because it can be changed into a prime (9978238577) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 193653 + ... + 239703.

It is an arithmetic number, because the mean of its divisors is an integer number (267746328).

Almost surely, 2^9978238578 is an apocalyptic number.

9978238578 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 9978238578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12851823744).

9978238578 is an abundant number, since it is smaller than the sum of its proper divisors (15725408910).

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

9978238578 is a wasteful number, since it uses less digits than its factorization.

9978238578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46148 (or 46141 counting only the distinct ones).

The product of its digits is 60963840, while the sum is 66.

The square root of 9978238578 is about 99891.1336305680. The cubic root of 9978238578 is about 2152.8707696296.

The spelling of 9978238578 in words is "nine billion, nine hundred seventy-eight million, two hundred thirty-eight thousand, five hundred seventy-eight".