21146664000 has 448 divisors, whose sum is σ = 87063754752. Its totient is φ = 4393728000.

The previous prime is 21146663999. The next prime is 21146664053. The reversal of 21146664000 is 46664112.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1842279 + ... + 1853721.

Almost surely, 2^21146664000 is an apocalyptic number.

21146664000 is a gapful number since it is divisible by the number (20) 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 21146664000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43531877376).

21146664000 is an abundant number, since it is smaller than the sum of its proper divisors (65917090752).

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

21146664000 is a wasteful number, since it uses less digits than its factorization.

21146664000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11491 (or 11471 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The spelling of 21146664000 in words is "twenty-one billion, one hundred forty-six million, six hundred sixty-four thousand".