9921940 has 48 divisors (see below), whose sum is σ = 24038784. Its totient is φ = 3369600.

The previous prime is 9921917. The next prime is 9921983. The reversal of 9921940 is 491299.

9921940 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 9921896 and 9921905.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18070 + ... + 18610.

It is an arithmetic number, because the mean of its divisors is an integer number (500808).

Almost surely, 2^9921940 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9921940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12019392).

9921940 is an abundant number, since it is smaller than the sum of its proper divisors (14116844).

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

9921940 is a wasteful number, since it uses less digits than its factorization.

9921940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 686 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 9921940 is about 3149.9111098569. The cubic root of 9921940 is about 214.8814200988.

The spelling of 9921940 in words is "nine million, nine hundred twenty-one thousand, nine hundred forty".