21943944 has 96 divisors (see below), whose sum is σ = 65707200. Its totient is φ = 6560640.

The previous prime is 21943937. The next prime is 21943973. The reversal of 21943944 is 44934912.

21943944 is a `hidden beast` number, since 219 + 439 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21943899 and 21943908.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81442 + ... + 81710.

It is an arithmetic number, because the mean of its divisors is an integer number (684450).

Almost surely, 2^21943944 is an apocalyptic number.

21943944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21943944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32853600).

21943944 is an abundant number, since it is smaller than the sum of its proper divisors (43763256).

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

21943944 is a wasteful number, since it uses less digits than its factorization.

21943944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395 (or 388 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 21943944 is about 4684.4363588376. The cubic root of 21943944 is about 279.9657441085.

The spelling of 21943944 in words is "twenty-one million, nine hundred forty-three thousand, nine hundred forty-four".