21433421431 has 2 divisors, whose sum is σ = 21433421432. Its totient is φ = 21433421430.

The previous prime is 21433421417. The next prime is 21433421461. The reversal of 21433421431 is 13412433412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21433421431 - 2⁹ = 21433420919 is a prime.

It is a super-2 number, since 2×21433421431² (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 21433421431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21433421461) 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, 10716710715 + 10716710716.

It is an arithmetic number, because the mean of its divisors is an integer number (10716710716).

Almost surely, 2^21433421431 is an apocalyptic number.

21433421431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21433421431 is an equidigital number, since it uses as much as digits as its factorization.

21433421431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 28.

Adding to 21433421431 its reverse (13412433412), we get a palindrome (34845854843).

The spelling of 21433421431 in words is "twenty-one billion, four hundred thirty-three million, four hundred twenty-one thousand, four hundred thirty-one".