21211022101 has 4 divisors (see below), whose sum is σ = 21230865100. Its totient is φ = 21191179104.

The previous prime is 21211022071. The next prime is 21211022113. The reversal of 21211022101 is 10122011212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5272212100 + 15938810001 = 72610^2 + 126249^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211022101 - 2¹⁷ = 21210891029 is a prime.

It is a super-2 number, since 2×21211022101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211022141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9919896 + ... + 9922033.

It is an arithmetic number, because the mean of its divisors is an integer number (5307716275).

Almost surely, 2^21211022101 is an apocalyptic number.

It is an amenable number.

21211022101 is a deficient number, since it is larger than the sum of its proper divisors (19842999).

21211022101 is a wasteful number, since it uses less digits than its factorization.

21211022101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19842998.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21211022101 its reverse (10122011212), we get a palindrome (31333033313).

The spelling of 21211022101 in words is "twenty-one billion, two hundred eleven million, twenty-two thousand, one hundred one".