221012221212221 has 16 divisors (see below), whose sum is σ = 232867150973184. Its totient is φ = 209344550747904.

The previous prime is 221012221212199. The next prime is 221012221212239. The reversal of 221012221212221 is 122212122210122.

It is a cyclic number.

It is not a de Polignac number, because 221012221212221 - 2¹⁴ = 221012221195837 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012221212821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82633925 + ... + 85266581.

It is an arithmetic number, because the mean of its divisors is an integer number (14554196935824).

Almost surely, 2^{221012221212221} is an apocalyptic number.

It is an amenable number.

221012221212221 is a deficient number, since it is larger than the sum of its proper divisors (11854929760963).

221012221212221 is a wasteful number, since it uses less digits than its factorization.

221012221212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668220.

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

Adding to 221012221212221 its reverse (122212122210122), we get a palindrome (343224343422343).

The spelling of 221012221212221 in words is "two hundred twenty-one trillion, twelve billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".