21001012000218 has 12 divisors (see below), whose sum is σ = 45502192667178. Its totient is φ = 7000337333400.

The previous prime is 21001012000211. The next prime is 21001012000231. The reversal of 21001012000218 is 81200021010012.

It can be written as a sum of positive squares in only one way, i.e., 19520694477729 + 1480317522489 = 4418223^2 + 1216683^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1166722888901 = 21001012000218 / (2 + 1 + 0 + 0 + 1 + 0 + 1 + 2 + 0 + 0 + 0 + 2 + 1 + 8).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21001012000218.

It is not an unprimeable number, because it can be changed into a prime (21001012000211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583361444433 + ... + 583361444468.

Almost surely, 2^{21001012000218} is an apocalyptic number.

21001012000218 is an abundant number, since it is smaller than the sum of its proper divisors (24501180666960).

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

21001012000218 is a wasteful number, since it uses less digits than its factorization.

21001012000218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1166722888909 (or 1166722888906 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The spelling of 21001012000218 in words is "twenty-one trillion, one billion, twelve million, two hundred eighteen", and thus it is an aban number.