21533430131 has 2 divisors, whose sum is σ = 21533430132. Its totient is φ = 21533430130.

The previous prime is 21533430091. The next prime is 21533430157. The reversal of 21533430131 is 13103433512.

It is an a-pointer prime, because the next prime (21533430157) can be obtained adding 21533430131 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21533430131 - 2⁶ = 21533430067 is a prime.

It is a super-2 number, since 2×21533430131² (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 21533430131.

It is not a weakly prime, because it can be changed into another prime (21533430031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766715065 + 10766715066.

It is an arithmetic number, because the mean of its divisors is an integer number (10766715066).

Almost surely, 2^21533430131 is an apocalyptic number.

21533430131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533430131 is an equidigital number, since it uses as much as digits as its factorization.

21533430131 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21533430131 its reverse (13103433512), we get a palindrome (34636863643).

The spelling of 21533430131 in words is "twenty-one billion, five hundred thirty-three million, four hundred thirty thousand, one hundred thirty-one".