21405384000 has 2016 divisors, whose sum is σ = 107423516928. Its totient is φ = 4105728000.

The previous prime is 21405383977. The next prime is 21405384103. The reversal of 21405384000 is 48350412.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1646567994 + ... + 1646568006.

Almost surely, 2^21405384000 is an apocalyptic number.

21405384000 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 21405384000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53711758464).

21405384000 is an abundant number, since it is smaller than the sum of its proper divisors (86018132928).

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

21405384000 is a wasteful number, since it uses less digits than its factorization.

21405384000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The spelling of 21405384000 in words is "twenty-one billion, four hundred five million, three hundred eighty-four thousand".