21220344302218 has 4 divisors (see below), whose sum is σ = 31830516453330. Its totient is φ = 10610172151108.

The previous prime is 21220344302197. The next prime is 21220344302219. The reversal of 21220344302218 is 81220344302212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15247174086169 + 5973170216049 = 3904763^2 + 2444007^2 .

It is not an unprimeable number, because it can be changed into a prime (21220344302219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5305086075553 + ... + 5305086075556.

Almost surely, 2^{21220344302218} is an apocalyptic number.

21220344302218 is a deficient number, since it is larger than the sum of its proper divisors (10610172151112).

21220344302218 is a wasteful number, since it uses less digits than its factorization.

21220344302218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10610172151111.

The product of its (nonzero) digits is 36864, while the sum is 34.

The spelling of 21220344302218 in words is "twenty-one trillion, two hundred twenty billion, three hundred forty-four million, three hundred two thousand, two hundred eighteen".