221000212021221 has 64 divisors (see below), whose sum is σ = 347098685472000. Its totient is φ = 138734582595840.

The previous prime is 221000212021217. The next prime is 221000212021231. The reversal of 221000212021221 is 122120212000122.

It is a happy number.

221000212021221 is a `hidden beast` number, since 2 + 210 + 0 + 0 + 212 + 0 + 21 + 221 = 666.

It is not a de Polignac number, because 221000212021221 - 2² = 221000212021217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221000212021194 and 221000212021203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221000212021231) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17290075 + ... + 27220343.

It is an arithmetic number, because the mean of its divisors is an integer number (5423416960500).

Almost surely, 2^{221000212021221} is an apocalyptic number.

It is an amenable number.

221000212021221 is a deficient number, since it is larger than the sum of its proper divisors (126098473450779).

221000212021221 is a wasteful number, since it uses less digits than its factorization.

221000212021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9931011 (or 9931005 counting only the distinct ones).

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

Adding to 221000212021221 its reverse (122120212000122), we get a palindrome (343120424021343).

The spelling of 221000212021221 in words is "two hundred twenty-one trillion, two hundred twelve million, twenty-one thousand, two hundred twenty-one".