211121122100221 has 16 divisors (see below), whose sum is σ = 217003977954288. Its totient is φ = 205273456128000.

The previous prime is 211121122100179. The next prime is 211121122100279. The reversal of 211121122100221 is 122001221121112.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 185931905419225 + 25189216680996 = 13635685^2 + 5018886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211121122100221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211121122100621) 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, 63848565 + ... + 67073701.

It is an arithmetic number, because the mean of its divisors is an integer number (13562748622143).

Almost surely, 2^{211121122100221} is an apocalyptic number.

It is an amenable number.

211121122100221 is a deficient number, since it is larger than the sum of its proper divisors (5882855854067).

211121122100221 is a wasteful number, since it uses less digits than its factorization.

211121122100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3230592.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 211121122100221 its reverse (122001221121112), we get a palindrome (333122343221333).

The spelling of 211121122100221 in words is "two hundred eleven trillion, one hundred twenty-one billion, one hundred twenty-two million, one hundred thousand, two hundred twenty-one".