21043533131 has 2 divisors, whose sum is σ = 21043533132. Its totient is φ = 21043533130.

The previous prime is 21043533089. The next prime is 21043533139. The reversal of 21043533131 is 13133534012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21043533131 - 2¹⁸ = 21043270987 is a prime.

It is a super-2 number, since 2×21043533131² (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 21043533131.

It is not a weakly prime, because it can be changed into another prime (21043533139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521766565 + 10521766566.

It is an arithmetic number, because the mean of its divisors is an integer number (10521766566).

Almost surely, 2^21043533131 is an apocalyptic number.

21043533131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043533131 is an equidigital number, since it uses as much as digits as its factorization.

21043533131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 26.

The spelling of 21043533131 in words is "twenty-one billion, forty-three million, five hundred thirty-three thousand, one hundred thirty-one".