21011432531 has 2 divisors, whose sum is σ = 21011432532. Its totient is φ = 21011432530.

The previous prime is 21011432503. The next prime is 21011432537. The reversal of 21011432531 is 13523411012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21011432531 - 2²² = 21007238227 is a prime.

It is a super-2 number, since 2×21011432531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011432497 and 21011432506.

It is not a weakly prime, because it can be changed into another prime (21011432537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505716265 + 10505716266.

It is an arithmetic number, because the mean of its divisors is an integer number (10505716266).

Almost surely, 2^21011432531 is an apocalyptic number.

21011432531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011432531 is an equidigital number, since it uses as much as digits as its factorization.

21011432531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

Adding to 21011432531 its reverse (13523411012), we get a palindrome (34534843543).

The spelling of 21011432531 in words is "twenty-one billion, eleven million, four hundred thirty-two thousand, five hundred thirty-one".