21355506000 has 480 divisors, whose sum is σ = 80481098880. Its totient is φ = 5260032000.

The previous prime is 21355505987. The next prime is 21355506031. The reversal of 21355506000 is 60555312.

21355506000 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 5 + 50 + 600 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14021239 + ... + 14022761.

It is an arithmetic number, because the mean of its divisors is an integer number (167668956).

Almost surely, 2^21355506000 is an apocalyptic number.

21355506000 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 21355506000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40240549440).

21355506000 is an abundant number, since it is smaller than the sum of its proper divisors (59125592880).

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

21355506000 is a wasteful number, since it uses less digits than its factorization.

21355506000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612 (or 1593 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The spelling of 21355506000 in words is "twenty-one billion, three hundred fifty-five million, five hundred six thousand".