21001222123031 has 2 divisors, whose sum is σ = 21001222123032. Its totient is φ = 21001222123030.

The previous prime is 21001222122997. The next prime is 21001222123093. The reversal of 21001222123031 is 13032122210012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21001222123031 is a prime.

It is a super-2 number, since 2×21001222123031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21001222122994 and 21001222123012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001222123631) 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 as a sum of consecutive naturals, namely, 10500611061515 + 10500611061516.

It is an arithmetic number, because the mean of its divisors is an integer number (10500611061516).

Almost surely, 2^{21001222123031} is an apocalyptic number.

21001222123031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001222123031 is an equidigital number, since it uses as much as digits as its factorization.

21001222123031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21001222123031 its reverse (13032122210012), we get a palindrome (34033344333043).

The spelling of 21001222123031 in words is "twenty-one trillion, one billion, two hundred twenty-two million, one hundred twenty-three thousand, thirty-one".