21544091239 has 4 divisors (see below), whose sum is σ = 23502645000. Its totient is φ = 19585537480.

The previous prime is 21544091209. The next prime is 21544091299. The reversal of 21544091239 is 93219044512.

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 21544091239 - 2⁵ = 21544091207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544091209) 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, 979276864 + ... + 979276885.

It is an arithmetic number, because the mean of its divisors is an integer number (5875661250).

Almost surely, 2^21544091239 is an apocalyptic number.

21544091239 is a deficient number, since it is larger than the sum of its proper divisors (1958553761).

21544091239 is a wasteful number, since it uses less digits than its factorization.

21544091239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1958553760.

The product of its (nonzero) digits is 77760, while the sum is 40.

The spelling of 21544091239 in words is "twenty-one billion, five hundred forty-four million, ninety-one thousand, two hundred thirty-nine".