21056101331 has 2 divisors, whose sum is σ = 21056101332. Its totient is φ = 21056101330.

The previous prime is 21056101309. The next prime is 21056101333. The reversal of 21056101331 is 13310165012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21056101331 - 2²⁶ = 20988992467 is a prime.

It is a super-2 number, since 2×21056101331² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 21056101333, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21056101297 and 21056101306.

It is not a weakly prime, because it can be changed into another prime (21056101333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10528050665 + 10528050666.

It is an arithmetic number, because the mean of its divisors is an integer number (10528050666).

Almost surely, 2^21056101331 is an apocalyptic number.

21056101331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21056101331 is an equidigital number, since it uses as much as digits as its factorization.

21056101331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 23.

Adding to 21056101331 its reverse (13310165012), we get a palindrome (34366266343).

The spelling of 21056101331 in words is "twenty-one billion, fifty-six million, one hundred one thousand, three hundred thirty-one".