21101212220201 has 4 divisors (see below), whose sum is σ = 21298419811152. Its totient is φ = 20904004629252.

The previous prime is 21101212220161. The next prime is 21101212220267. The reversal of 21101212220201 is 10202221210112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21101212220201 - 2²² = 21101208025897 is a prime.

It is a super-2 number, since 2×21101212220201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21101212220201.

It is not an unprimeable number, because it can be changed into a prime (21101212220801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98603795315 + ... + 98603795528.

It is an arithmetic number, because the mean of its divisors is an integer number (5324604952788).

Almost surely, 2^{21101212220201} is an apocalyptic number.

It is an amenable number.

21101212220201 is a deficient number, since it is larger than the sum of its proper divisors (197207590951).

21101212220201 is a wasteful number, since it uses less digits than its factorization.

21101212220201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197207590950.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21101212220201 its reverse (10202221210112), we get a palindrome (31303433430313).

The spelling of 21101212220201 in words is "twenty-one trillion, one hundred one billion, two hundred twelve million, two hundred twenty thousand, two hundred one".