21020131331 has 2 divisors, whose sum is σ = 21020131332. Its totient is φ = 21020131330.

The previous prime is 21020131271. The next prime is 21020131333. The reversal of 21020131331 is 13313102012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21020131331 - 2³⁴ = 3840262147 is a prime.

It is a super-3 number, since 3×21020131331³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 21020131333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21020131333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510065665 + 10510065666.

It is an arithmetic number, because the mean of its divisors is an integer number (10510065666).

Almost surely, 2^21020131331 is an apocalyptic number.

21020131331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020131331 is an equidigital number, since it uses as much as digits as its factorization.

21020131331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21020131331 its reverse (13313102012), we get a palindrome (34333233343).

The spelling of 21020131331 in words is "twenty-one billion, twenty million, one hundred thirty-one thousand, three hundred thirty-one".