21943584639 has 32 divisors (see below), whose sum is σ = 33612871680. Its totient is φ = 14133873600.

The previous prime is 21943584601. The next prime is 21943584667. The reversal of 21943584639 is 93648534912.

21943584639 is a `hidden beast` number, since 2 + 19 + 43 + 584 + 6 + 3 + 9 = 666.

It is not a de Polignac number, because 21943584639 - 2³¹ = 19796100991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21943584679) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 495184 + ... + 537674.

It is an arithmetic number, because the mean of its divisors is an integer number (1050402240).

Almost surely, 2^21943584639 is an apocalyptic number.

21943584639 is a deficient number, since it is larger than the sum of its proper divisors (11669287041).

21943584639 is a wasteful number, since it uses less digits than its factorization.

21943584639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43148 (or 43142 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The spelling of 21943584639 in words is "twenty-one billion, nine hundred forty-three million, five hundred eighty-four thousand, six hundred thirty-nine".