21647053824 has 176 divisors, whose sum is σ = 63510713280. Its totient is φ = 6500515840.

The previous prime is 21647053817. The next prime is 21647053849. The reversal of 21647053824 is 42835074612.

It is a tau number, because it is divible by the number of its divisors (176).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3815662 + ... + 3821330.

Almost surely, 2^21647053824 is an apocalyptic number.

21647053824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21647053824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31755356640).

21647053824 is an abundant number, since it is smaller than the sum of its proper divisors (41863659456).

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

21647053824 is a wasteful number, since it uses less digits than its factorization.

21647053824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5816 (or 5798 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 42.

The spelling of 21647053824 in words is "twenty-one billion, six hundred forty-seven million, fifty-three thousand, eight hundred twenty-four".