21684843024 has 40 divisors (see below), whose sum is σ = 60328347072. Its totient is φ = 6672259200.

The previous prime is 21684843023. The next prime is 21684843029. The reversal of 21684843024 is 42034848612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21684843023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17375052 + ... + 17376299.

Almost surely, 2^21684843024 is an apocalyptic number.

21684843024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21684843024 is an abundant number, since it is smaller than the sum of its proper divisors (38643504048).

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

21684843024 is a wasteful number, since it uses less digits than its factorization.

21684843024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34751375 (or 34751369 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 42.

The spelling of 21684843024 in words is "twenty-one billion, six hundred eighty-four million, eight hundred forty-three thousand, twenty-four".