21201111122001 has 16 divisors (see below), whose sum is σ = 29498705153664. Its totient is φ = 13518858380544.

The previous prime is 21201111121987. The next prime is 21201111122057. The reversal of 21201111122001 is 10022111110212.

It is a happy number.

It is not a de Polignac number, because 21201111122001 - 2¹¹ = 21201111119953 is a prime.

It is a super-2 number, since 2×21201111122001² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21201111120001) 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, 6487336 + ... + 9191721.

It is an arithmetic number, because the mean of its divisors is an integer number (1843669072104).

Almost surely, 2^{21201111122001} is an apocalyptic number.

It is an amenable number.

21201111122001 is a deficient number, since it is larger than the sum of its proper divisors (8297594031663).

21201111122001 is a wasteful number, since it uses less digits than its factorization.

21201111122001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15698680.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21201111122001 its reverse (10022111110212), we get a palindrome (31223222232213).

The spelling of 21201111122001 in words is "twenty-one trillion, two hundred one billion, one hundred eleven million, one hundred twenty-two thousand, one".