21043123333431 has 4 divisors (see below), whose sum is σ = 28057497777912. Its totient is φ = 14028748888952.

The previous prime is 21043123333409. The next prime is 21043123333433. The reversal of 21043123333431 is 13433332134012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21043123333431 - 2⁶ = 21043123333367 is a prime.

It is a super-2 number, since 2×21043123333431² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21043123333392 and 21043123333401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043123333433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3507187222236 + ... + 3507187222241.

It is an arithmetic number, because the mean of its divisors is an integer number (7014374444478).

Almost surely, 2^{21043123333431} is an apocalyptic number.

21043123333431 is a deficient number, since it is larger than the sum of its proper divisors (7014374444481).

21043123333431 is an equidigital number, since it uses as much as digits as its factorization.

21043123333431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7014374444480.

The product of its (nonzero) digits is 46656, while the sum is 33.

Adding to 21043123333431 its reverse (13433332134012), we get a palindrome (34476455467443).

The spelling of 21043123333431 in words is "twenty-one trillion, forty-three billion, one hundred twenty-three million, three hundred thirty-three thousand, four hundred thirty-one".