21516354000 has 200 divisors, whose sum is σ = 77719249608. Its totient is φ = 5737651200.

The previous prime is 21516353941. The next prime is 21516354007. The reversal of 21516354000 is 45361512.

21516354000 is a `hidden beast` number, since 21 + 5 + 1 + 635 + 4 + 0 + 0 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3330213264 + 18186140736 = 57708^2 + 134856^2 .

It is a tau number, because it is divible by the number of its divisors (200).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516354007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 95592 + ... + 228408.

Almost surely, 2^21516354000 is an apocalyptic number.

21516354000 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 21516354000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38859624804).

21516354000 is an abundant number, since it is smaller than the sum of its proper divisors (56202895608).

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

21516354000 is a wasteful number, since it uses less digits than its factorization.

21516354000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132852 (or 132827 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 21516354000 in words is "twenty-one billion, five hundred sixteen million, three hundred fifty-four thousand".