21444559 has 4 divisors (see below), whose sum is σ = 22573240. Its totient is φ = 20315880.

The previous prime is 21444541. The next prime is 21444581. The reversal of 21444559 is 95544412.

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 21444559 - 2⁷ = 21444431 is a prime.

It is a super-2 number, since 2×21444559² = 919738221408962, 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 (21444589) 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, 564312 + ... + 564349.

It is an arithmetic number, because the mean of its divisors is an integer number (5643310).

Almost surely, 2^21444559 is an apocalyptic number.

21444559 is a deficient number, since it is larger than the sum of its proper divisors (1128681).

21444559 is a wasteful number, since it uses less digits than its factorization.

21444559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128680.

The product of its digits is 28800, while the sum is 34.

The square root of 21444559 is about 4630.8270319674. The cubic root of 21444559 is about 277.8256718069.

The spelling of 21444559 in words is "twenty-one million, four hundred forty-four thousand, five hundred fifty-nine".