21001222231231 has 12 divisors (see below), whose sum is σ = 23727680775864. Its totient is φ = 18433674677600.

The previous prime is 21001222231211. The next prime is 21001222231237. The reversal of 21001222231231 is 13213222210012.

It is not a de Polignac number, because 21001222231231 - 2⁹ = 21001222230719 is a prime.

It is a super-2 number, since 2×21001222231231² (a number of 27 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 (21001222231237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1135069240 + ... + 1135087741.

It is an arithmetic number, because the mean of its divisors is an integer number (1977306731322).

Almost surely, 2^{21001222231231} is an apocalyptic number.

21001222231231 is a deficient number, since it is larger than the sum of its proper divisors (2726458544633).

21001222231231 is a wasteful number, since it uses less digits than its factorization.

21001222231231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2270157050 (or 2270157021 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 21001222231231 its reverse (13213222210012), we get a palindrome (34214444441243).

The spelling of 21001222231231 in words is "twenty-one trillion, one billion, two hundred twenty-two million, two hundred thirty-one thousand, two hundred thirty-one".