21600001836 has 144 divisors (see below), whose sum is σ = 65249906400. Its totient is φ = 6161291136.

The previous prime is 21600001783. The next prime is 21600001849. The reversal of 21600001836 is 63810000612.

21600001836 is a `hidden beast` number, since 21 + 600 + 0 + 0 + 1 + 8 + 36 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3579670 + ... + 3585698.

It is an arithmetic number, because the mean of its divisors is an integer number (453124350).

Almost surely, 2^21600001836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21600001836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32624953200).

21600001836 is an abundant number, since it is smaller than the sum of its proper divisors (43649904564).

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

21600001836 is a wasteful number, since it uses less digits than its factorization.

21600001836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6733 (or 6718 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The spelling of 21600001836 in words is "twenty-one billion, six hundred million, one thousand, eight hundred thirty-six".