9891989070 has 64 divisors (see below), whose sum is σ = 25161627456. Its totient is φ = 2480291840.

The previous prime is 9891989039. The next prime is 9891989083. The reversal of 9891989070 is 709891989.

It is a junction number, because it is equal to n+sod(n) for n = 9891988995 and 9891989013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 550630 + ... + 568310.

It is an arithmetic number, because the mean of its divisors is an integer number (393150429).

Almost surely, 2^9891989070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9891989070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12580813728).

9891989070 is an abundant number, since it is smaller than the sum of its proper divisors (15269638386).

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

9891989070 is a wasteful number, since it uses less digits than its factorization.

9891989070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18805.

The product of its (nonzero) digits is 2939328, while the sum is 60.

The square root of 9891989070 is about 99458.4791257136. The cubic root of 9891989070 is about 2146.6498442940.

The spelling of 9891989070 in words is "nine billion, eight hundred ninety-one million, nine hundred eighty-nine thousand, seventy".