21005524244 has 12 divisors (see below), whose sum is σ = 36865605504. Its totient is φ = 10472494104.

The previous prime is 21005524231. The next prime is 21005524247. The reversal of 21005524244 is 44242550012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005524247) 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, 7565444 + ... + 7568219.

It is an arithmetic number, because the mean of its divisors is an integer number (3072133792).

Almost surely, 2^21005524244 is an apocalyptic number.

It is an amenable number.

21005524244 is a deficient number, since it is larger than the sum of its proper divisors (15860081260).

21005524244 is a wasteful number, since it uses less digits than its factorization.

21005524244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15134014 (or 15134012 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 29.

The spelling of 21005524244 in words is "twenty-one billion, five million, five hundred twenty-four thousand, two hundred forty-four".