21944719 has 4 divisors (see below), whose sum is σ = 21966880. Its totient is φ = 21922560.

The previous prime is 21944701. The next prime is 21944759. The reversal of 21944719 is 91744912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21944719 - 2¹³ = 21936527 is a prime.

It is a super-2 number, since 2×21944719² = 963141383977922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21944759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9522 + ... + 11599.

It is an arithmetic number, because the mean of its divisors is an integer number (5491720).

Almost surely, 2^21944719 is an apocalyptic number.

21944719 is a deficient number, since it is larger than the sum of its proper divisors (22161).

21944719 is a wasteful number, since it uses less digits than its factorization.

21944719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22160.

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

The square root of 21944719 is about 4684.5190788383. The cubic root of 21944719 is about 279.9690399442.

The spelling of 21944719 in words is "twenty-one million, nine hundred forty-four thousand, seven hundred nineteen".