21000002002218 has 96 divisors (see below), whose sum is σ = 47406471630336. Its totient is φ = 6967186031808.

The previous prime is 21000002002211. The next prime is 21000002002219. The reversal of 21000002002218 is 81220020000012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21000002002218.

It is not an unprimeable number, because it can be changed into a prime (21000002002211) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 619580080 + ... + 619613972.

It is an arithmetic number, because the mean of its divisors is an integer number (493817412816).

Almost surely, 2^{21000002002218} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000002002218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23703235815168).

21000002002218 is an abundant number, since it is smaller than the sum of its proper divisors (26406469628118).

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

21000002002218 is a wasteful number, since it uses less digits than its factorization.

21000002002218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39850 (or 39838 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The spelling of 21000002002218 in words is "twenty-one trillion, two million, two thousand, two hundred eighteen".