20041221218 has 6 divisors (see below), whose sum is σ = 30062132139. Its totient is φ = 10020510506.

The previous prime is 20041221209. The next prime is 20041221227. The reversal of 20041221218 is 81212214002.

It is an interprime number because it is at equal distance from previous prime (20041221209) and next prime (20041221227).

It can be written as a sum of positive squares in only one way, i.e., 10020610609 + 10020610609 = 100103^2 + 100103^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=100103.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20041221193 and 20041221202.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 150155 + ... + 250257.

Almost surely, 2^20041221218 is an apocalyptic number.

20041221218 is a deficient number, since it is larger than the sum of its proper divisors (10020910921).

20041221218 is an frugal number, since it uses more digits than its factorization.

20041221218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200208 (or 100105 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

Multiplying 20041221218 by its product of nonzero digits (512), we get a square (10261105263616 = 3203296²).

The spelling of 20041221218 in words is "twenty billion, forty-one million, two hundred twenty-one thousand, two hundred eighteen".