21435543431 has 4 divisors (see below), whose sum is σ = 21436159200. Its totient is φ = 21434927664.

The previous prime is 21435543379. The next prime is 21435543439. The reversal of 21435543431 is 13434553412.

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 21435543431 - 2¹⁰ = 21435542407 is a prime.

It is a super-2 number, since 2×21435543431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21435543391 and 21435543400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21435543439) 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, 252326 + ... + 326403.

It is an arithmetic number, because the mean of its divisors is an integer number (5359039800).

Almost surely, 2^21435543431 is an apocalyptic number.

21435543431 is a deficient number, since it is larger than the sum of its proper divisors (615769).

21435543431 is an equidigital number, since it uses as much as digits as its factorization.

21435543431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615768.

The product of its digits is 86400, while the sum is 35.

The spelling of 21435543431 in words is "twenty-one billion, four hundred thirty-five million, five hundred forty-three thousand, four hundred thirty-one".