21041666688 has 128 divisors (see below), whose sum is σ = 63922176000. Its totient is φ = 6007606272.

The previous prime is 21041666651. The next prime is 21041666689. The reversal of 21041666688 is 88666614012.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (21041666689) 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, 7307233 + ... + 7310111.

It is an arithmetic number, because the mean of its divisors is an integer number (499392000).

Almost surely, 2^21041666688 is an apocalyptic number.

21041666688 is a gapful number since it is divisible by the number (28) 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 21041666688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31961088000).

21041666688 is an abundant number, since it is smaller than the sum of its proper divisors (42880509312).

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

21041666688 is a wasteful number, since it uses less digits than its factorization.

21041666688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5622 (or 5610 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 48.

The spelling of 21041666688 in words is "twenty-one billion, forty-one million, six hundred sixty-six thousand, six hundred eighty-eight".