9801812643840 has 2080 divisors, whose sum is σ = 42132461623296. Its totient is φ = 2132709212160.

The previous prime is 9801812643823. The next prime is 9801812643851. The reversal of 9801812643840 is 483462181089.

It is a happy number.

9801812643840 is a `hidden beast` number, since 9 + 8 + 0 + 181 + 26 + 438 + 4 + 0 = 666.

It is a super-2 number, since 2×9801812643840² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 26278317894 + ... + 26278318266.

Almost surely, 2^{9801812643840} is an apocalyptic number.

9801812643840 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 9801812643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21066230811648).

9801812643840 is an abundant number, since it is smaller than the sum of its proper divisors (32330648979456).

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

9801812643840 is a wasteful number, since it uses less digits than its factorization.

9801812643840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525 (or 494 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 54.

The spelling of 9801812643840 in words is "nine trillion, eight hundred one billion, eight hundred twelve million, six hundred forty-three thousand, eight hundred forty".