9990990870 has 128 divisors (see below), whose sum is σ = 27713664000. Its totient is φ = 2257992192.

The previous prime is 9990990857. The next prime is 9990990871. The reversal of 9990990870 is 780990999.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9990990871) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8416417 + ... + 8417603.

It is an arithmetic number, because the mean of its divisors is an integer number (216513000).

Almost surely, 2^9990990870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9990990870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13856832000).

9990990870 is an abundant number, since it is smaller than the sum of its proper divisors (17722673130).

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

9990990870 is a wasteful number, since it uses less digits than its factorization.

9990990870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622.

The product of its (nonzero) digits is 3306744, while the sum is 60.

The square root of 9990990870 is about 99954.9441998744. The cubic root of 9990990870 is about 2153.7875095686.

The spelling of 9990990870 in words is "nine billion, nine hundred ninety million, nine hundred ninety thousand, eight hundred seventy".