21644486372 has 12 divisors (see below), whose sum is σ = 38011697136. Its totient is φ = 10784001480.

The previous prime is 21644486267. The next prime is 21644486393. The reversal of 21644486372 is 27368444612.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9559154 + ... + 9561417.

It is an arithmetic number, because the mean of its divisors is an integer number (3167641428).

Almost surely, 2^21644486372 is an apocalyptic number.

It is an amenable number.

21644486372 is a deficient number, since it is larger than the sum of its proper divisors (16367210764).

21644486372 is a wasteful number, since it uses less digits than its factorization.

21644486372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19120858 (or 19120856 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 47.

The spelling of 21644486372 in words is "twenty-one billion, six hundred forty-four million, four hundred eighty-six thousand, three hundred seventy-two".