21144235433 has 2 divisors, whose sum is σ = 21144235434. Its totient is φ = 21144235432.

The previous prime is 21144235391. The next prime is 21144235459. The reversal of 21144235433 is 33453244112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20956326169 + 187909264 = 144763^2 + 13708^2 .

It is a cyclic number.

It is not a de Polignac number, because 21144235433 - 2¹⁶ = 21144169897 is a prime.

It is a super-2 number, since 2×21144235433² (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 21144235433.

It is not a weakly prime, because it can be changed into another prime (21144235933) 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, 10572117716 + 10572117717.

It is an arithmetic number, because the mean of its divisors is an integer number (10572117717).

Almost surely, 2^21144235433 is an apocalyptic number.

It is an amenable number.

21144235433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144235433 is an equidigital number, since it uses as much as digits as its factorization.

21144235433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 32.

Adding to 21144235433 its reverse (33453244112), we get a palindrome (54597479545).

The spelling of 21144235433 in words is "twenty-one billion, one hundred forty-four million, two hundred thirty-five thousand, four hundred thirty-three".