211221212221001 has 16 divisors (see below), whose sum is σ = 213598574931600. Its totient is φ = 208849512960000.

The previous prime is 211221212220989. The next prime is 211221212221051. The reversal of 211221212221001 is 100122212122112.

It can be written as a sum of positive squares in 8 ways, for example, as 165330735610000 + 45890476611001 = 12858100^2 + 6774251^2 .

It is not a de Polignac number, because 211221212221001 - 2⁶ = 211221212220937 is a prime.

It is a super-2 number, since 2×211221212221001² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211221212221051) 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, 808870265 + ... + 809131353.

It is an arithmetic number, because the mean of its divisors is an integer number (13349910933225).

Almost surely, 2^{211221212221001} is an apocalyptic number.

It is an amenable number.

211221212221001 is a deficient number, since it is larger than the sum of its proper divisors (2377362710599).

211221212221001 is a wasteful number, since it uses less digits than its factorization.

211221212221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271900.

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

Adding to 211221212221001 its reverse (100122212122112), we get a palindrome (311343424343113).

The spelling of 211221212221001 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, one".