21600018036 has 48 divisors (see below), whose sum is σ = 56375928000. Its totient is φ = 7151678496.

The previous prime is 21600018031. The next prime is 21600018053. The reversal of 21600018036 is 63081000612.

21600018036 is a `hidden beast` number, since 21 + 600 + 0 + 1 + 8 + 0 + 36 = 666.

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 (21600018031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 655050 + ... + 687233.

It is an arithmetic number, because the mean of its divisors is an integer number (1174498500).

Almost surely, 2^21600018036 is an apocalyptic number.

It is an amenable number.

21600018036 is an abundant number, since it is smaller than the sum of its proper divisors (34775909964).

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

21600018036 is a wasteful number, since it uses less digits than its factorization.

21600018036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342445 (or 1342437 counting only the distinct ones).

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

Adding to 21600018036 its reverse (63081000612), we get a palindrome (84681018648).

The spelling of 21600018036 in words is "twenty-one billion, six hundred million, eighteen thousand, thirty-six".