21944791 has 8 divisors (see below), whose sum is σ = 25200000. Its totient is φ = 18899640.

The previous prime is 21944789. The next prime is 21944827. The reversal of 21944791 is 19744912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21944791 - 2¹ = 21944789 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21944791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21944701) 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, 52291 + ... + 52708.

It is an arithmetic number, because the mean of its divisors is an integer number (3150000).

Almost surely, 2^21944791 is an apocalyptic number.

21944791 is a deficient number, since it is larger than the sum of its proper divisors (3255209).

21944791 is a wasteful number, since it uses less digits than its factorization.

21944791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105029.

The product of its digits is 18144, while the sum is 37.

The square root of 21944791 is about 4684.5267637190. The cubic root of 21944791 is about 279.9693461340.

The spelling of 21944791 in words is "twenty-one million, nine hundred forty-four thousand, seven hundred ninety-one".