9971920 has 40 divisors (see below), whose sum is σ = 26498304. Its totient is φ = 3418752.

The previous prime is 9971917. The next prime is 9971921. The reversal of 9971920 is 291799.

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

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 9971920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9971921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8344 + ... + 9463.

Almost surely, 2^9971920 is an apocalyptic number.

It is an amenable number.

9971920 is an abundant number, since it is smaller than the sum of its proper divisors (16526384).

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

9971920 is a wasteful number, since it uses less digits than its factorization.

9971920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17827 (or 17821 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 9971920 is about 3157.8347011837. The cubic root of 9971920 is about 215.2416248720.

The spelling of 9971920 in words is "nine million, nine hundred seventy-one thousand, nine hundred twenty".