21331355131 has 2 divisors, whose sum is σ = 21331355132. Its totient is φ = 21331355130.

The previous prime is 21331355063. The next prime is 21331355141. The reversal of 21331355131 is 13155313312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21331355131 - 2¹⁷ = 21331224059 is a prime.

It is a super-2 number, since 2×21331355131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21331355131.

It is not a weakly prime, because it can be changed into another prime (21331355141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665677565 + 10665677566.

It is an arithmetic number, because the mean of its divisors is an integer number (10665677566).

Almost surely, 2^21331355131 is an apocalyptic number.

21331355131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331355131 is an equidigital number, since it uses as much as digits as its factorization.

21331355131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4050, while the sum is 28.

Adding to 21331355131 its reverse (13155313312), we get a palindrome (34486668443).

The spelling of 21331355131 in words is "twenty-one billion, three hundred thirty-one million, three hundred fifty-five thousand, one hundred thirty-one".