21435345231 has 4 divisors (see below), whose sum is σ = 28580460312. Its totient is φ = 14290230152.

The previous prime is 21435345227. The next prime is 21435345233. The reversal of 21435345231 is 13254353412.

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 21435345231 - 2² = 21435345227 is a prime.

It is a super-2 number, since 2×21435345231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21435345192 and 21435345201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21435345233) 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, 3572557536 + ... + 3572557541.

It is an arithmetic number, because the mean of its divisors is an integer number (7145115078).

Almost surely, 2^21435345231 is an apocalyptic number.

21435345231 is a deficient number, since it is larger than the sum of its proper divisors (7145115081).

21435345231 is an equidigital number, since it uses as much as digits as its factorization.

21435345231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7145115080.

The product of its digits is 43200, while the sum is 33.

Adding to 21435345231 its reverse (13254353412), we get a palindrome (34689698643).

The spelling of 21435345231 in words is "twenty-one billion, four hundred thirty-five million, three hundred forty-five thousand, two hundred thirty-one".