21043443431207 has 2 divisors, whose sum is σ = 21043443431208. Its totient is φ = 21043443431206.

The previous prime is 21043443431177. The next prime is 21043443431239. The reversal of 21043443431207 is 70213434434012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21043443431207 - 2¹⁴ = 21043443414823 is a prime.

It is a super-2 number, since 2×21043443431207² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21043443437207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521721715603 + 10521721715604.

It is an arithmetic number, because the mean of its divisors is an integer number (10521721715604).

Almost surely, 2^{21043443431207} is an apocalyptic number.

21043443431207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043443431207 is an equidigital number, since it uses as much as digits as its factorization.

21043443431207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 38.

Adding to 21043443431207 its reverse (70213434434012), we get a palindrome (91256877865219).

The spelling of 21043443431207 in words is "twenty-one trillion, forty-three billion, four hundred forty-three million, four hundred thirty-one thousand, two hundred seven".