21841989520 has 80 divisors (see below), whose sum is σ = 55381455360. Its totient is φ = 7962619392.

The previous prime is 21841989493. The next prime is 21841989527. The reversal of 21841989520 is 2598914812.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21841989527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50764 + ... + 215083.

It is an arithmetic number, because the mean of its divisors is an integer number (692268192).

Almost surely, 2^21841989520 is an apocalyptic number.

21841989520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21841989520 is an abundant number, since it is smaller than the sum of its proper divisors (33539465840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21841989520 is a wasteful number, since it uses less digits than its factorization.

21841989520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265952 (or 265946 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 49.

The spelling of 21841989520 in words is "twenty-one billion, eight hundred forty-one million, nine hundred eighty-nine thousand, five hundred twenty".