9913811920 has 40 divisors (see below), whose sum is σ = 23062914504. Its totient is φ = 3963236352.

The previous prime is 9913811899. The next prime is 9913812017. The reversal of 9913811920 is 291183199.

It can be written as a sum of positive squares in 4 ways, for example, as 1013021584 + 8900790336 = 31828^2 + 94344^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107292 + ... + 177028.

Almost surely, 2^9913811920 is an apocalyptic number.

It is an amenable number.

9913811920 is an abundant number, since it is smaller than the sum of its proper divisors (13149102584).

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

9913811920 is a wasteful number, since it uses less digits than its factorization.

9913811920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71527 (or 71521 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 9913811920 is about 99568.1270286832. The cubic root of 9913811920 is about 2148.2272692242.

The spelling of 9913811920 in words is "nine billion, nine hundred thirteen million, eight hundred eleven thousand, nine hundred twenty".