212100121221 has 16 divisors (see below), whose sum is σ = 286904596608. Its totient is φ = 139349548800.

The previous prime is 212100121193. The next prime is 212100121241. The reversal of 212100121221 is 122121001212.

It is not a de Polignac number, because 212100121221 - 2¹⁸ = 212099859077 is a prime.

It is a super-2 number, since 2×212100121221² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 212100121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212100121241) 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, 296841 + ... + 715761.

It is an arithmetic number, because the mean of its divisors is an integer number (17931537288).

Almost surely, 2^212100121221 is an apocalyptic number.

It is an amenable number.

212100121221 is a deficient number, since it is larger than the sum of its proper divisors (74804475387).

212100121221 is a wasteful number, since it uses less digits than its factorization.

212100121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421372.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 212100121221 its reverse (122121001212), we get a palindrome (334221122433).

The spelling of 212100121221 in words is "two hundred twelve billion, one hundred million, one hundred twenty-one thousand, two hundred twenty-one".