21210020020031 has 2 divisors, whose sum is σ = 21210020020032. Its totient is φ = 21210020020030.

The previous prime is 21210020020019. The next prime is 21210020020117. The reversal of 21210020020031 is 13002002001212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21210020020031 - 2⁶ = 21210020019967 is a prime.

It is a super-2 number, since 2×21210020020031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21210020019988 and 21210020020015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210020020331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605010010015 + 10605010010016.

It is an arithmetic number, because the mean of its divisors is an integer number (10605010010016).

Almost surely, 2^{21210020020031} is an apocalyptic number.

21210020020031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210020020031 is an equidigital number, since it uses as much as digits as its factorization.

21210020020031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21210020020031 its reverse (13002002001212), we get a palindrome (34212022021243).

The spelling of 21210020020031 in words is "twenty-one trillion, two hundred ten billion, twenty million, twenty thousand, thirty-one".