9811920 has 40 divisors (see below), whose sum is σ = 30417696. Its totient is φ = 2616448.

The previous prime is 9811909. The next prime is 9811933. The reversal of 9811920 is 291189.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20202 + ... + 20681.

Almost surely, 2^9811920 is an apocalyptic number.

It is an amenable number.

9811920 is an abundant number, since it is smaller than the sum of its proper divisors (20605776).

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

9811920 is a wasteful number, since it uses less digits than its factorization.

9811920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40899 (or 40893 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 9811920 is about 3132.3984420887. The cubic root of 9811920 is about 214.0842245698.

It can be divided in two parts, 9811 and 920, that added together give a triangular number (10731 = T₁₄₆).

The spelling of 9811920 in words is "nine million, eight hundred eleven thousand, nine hundred twenty".