21324342431 has 4 divisors (see below), whose sum is σ = 24370677072. Its totient is φ = 18278007792.

The previous prime is 21324342419. The next prime is 21324342443. The reversal of 21324342431 is 13424342312.

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

It is an interprime number because it is at equal distance from previous prime (21324342419) and next prime (21324342443).

It is a cyclic number.

It is not a de Polignac number, because 21324342431 - 2¹⁰ = 21324341407 is a prime.

It is a super-2 number, since 2×21324342431² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21324342394 and 21324342403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324342401) 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, 1523167310 + ... + 1523167323.

It is an arithmetic number, because the mean of its divisors is an integer number (6092669268).

Almost surely, 2^21324342431 is an apocalyptic number.

21324342431 is a deficient number, since it is larger than the sum of its proper divisors (3046334641).

21324342431 is an equidigital number, since it uses as much as digits as its factorization.

21324342431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3046334640.

The product of its digits is 13824, while the sum is 29.

Adding to 21324342431 its reverse (13424342312), we get a palindrome (34748684743).

The spelling of 21324342431 in words is "twenty-one billion, three hundred twenty-four million, three hundred forty-two thousand, four hundred thirty-one".