221221010018 has 8 divisors (see below), whose sum is σ = 331871903580. Its totient is φ = 110597042160.

The previous prime is 221221010011. The next prime is 221221010027. The reversal of 221221010018 is 810010122122.

It can be written as a sum of positive squares in 2 ways, for example, as 166678677169 + 54542332849 = 408263^2 + 233543^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (221221010011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6710873 + ... + 6743756.

Almost surely, 2^221221010018 is an apocalyptic number.

221221010018 is a deficient number, since it is larger than the sum of its proper divisors (110650893562).

221221010018 is a wasteful number, since it uses less digits than its factorization.

221221010018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13462852.

The product of its (nonzero) digits is 128, while the sum is 20.

The spelling of 221221010018 in words is "two hundred twenty-one billion, two hundred twenty-one million, ten thousand, eighteen".