21220111001001 has 16 divisors (see below), whose sum is σ = 31300342990848. Its totient is φ = 12679537088400.

The previous prime is 21220111000931. The next prime is 21220111001039. The reversal of 21220111001001 is 10010011102212.

It is not a de Polignac number, because 21220111001001 - 2⁹ = 21220111000489 is a prime.

It is a super-2 number, since 2×21220111001001² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21220111001071) 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, 4528403761 + ... + 4528408446.

It is an arithmetic number, because the mean of its divisors is an integer number (1956271436928).

Almost surely, 2^{21220111001001} is an apocalyptic number.

It is an amenable number.

21220111001001 is a deficient number, since it is larger than the sum of its proper divisors (10080231989847).

21220111001001 is a wasteful number, since it uses less digits than its factorization.

21220111001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9056812292.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21220111001001 its reverse (10010011102212), we get a palindrome (31230122103213).

The spelling of 21220111001001 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, one thousand, one".