21212120001031 has 2 divisors, whose sum is σ = 21212120001032. Its totient is φ = 21212120001030.

The previous prime is 21212120000989. The next prime is 21212120001043. The reversal of 21212120001031 is 13010002121212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212120001031 is a prime.

It is a super-2 number, since 2×21212120001031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21212120000996 and 21212120001014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212120001071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606060000515 + 10606060000516.

It is an arithmetic number, because the mean of its divisors is an integer number (10606060000516).

Almost surely, 2^{21212120001031} is an apocalyptic number.

21212120001031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212120001031 is an equidigital number, since it uses as much as digits as its factorization.

21212120001031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21212120001031 its reverse (13010002121212), we get a palindrome (34222122122243).

The spelling of 21212120001031 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty million, one thousand, thirty-one".