21000220221031 has 2 divisors, whose sum is σ = 21000220221032. Its totient is φ = 21000220221030.

The previous prime is 21000220221007. The next prime is 21000220221037. The reversal of 21000220221031 is 13012202200012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000220221031 - 2³⁹ = 20450464407143 is a prime.

It is a super-2 number, since 2×21000220221031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21000220220996 and 21000220221014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000220221037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500110110515 + 10500110110516.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110110516).

Almost surely, 2^{21000220221031} is an apocalyptic number.

21000220221031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000220221031 is an equidigital number, since it uses as much as digits as its factorization.

21000220221031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21000220221031 its reverse (13012202200012), we get a palindrome (34012422421043).

The spelling of 21000220221031 in words is "twenty-one trillion, two hundred twenty million, two hundred twenty-one thousand, thirty-one".