211101111021221 has 16 divisors (see below), whose sum is σ = 226890001200960. Its totient is φ = 195687713168640.

The previous prime is 211101111021161. The next prime is 211101111021277. The reversal of 211101111021221 is 122120111101112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211101111021221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 211101111021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211101111021821) 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, 6956975 + ... + 21693356.

It is an arithmetic number, because the mean of its divisors is an integer number (14180625075060).

Almost surely, 2^{211101111021221} is an apocalyptic number.

It is an amenable number.

211101111021221 is a deficient number, since it is larger than the sum of its proper divisors (15788890179739).

211101111021221 is a wasteful number, since it uses less digits than its factorization.

211101111021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28656884.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 211101111021221 its reverse (122120111101112), we get a palindrome (333221222122333).

The spelling of 211101111021221 in words is "two hundred eleven trillion, one hundred one billion, one hundred eleven million, twenty-one thousand, two hundred twenty-one".