21340414243 has 4 divisors (see below), whose sum is σ = 22463593960. Its totient is φ = 20217234528.

The previous prime is 21340414241. The next prime is 21340414267. The reversal of 21340414243 is 34241404312.

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 21340414243 - 2¹ = 21340414241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21340414241) 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, 561589830 + ... + 561589867.

It is an arithmetic number, because the mean of its divisors is an integer number (5615898490).

Almost surely, 2^21340414243 is an apocalyptic number.

21340414243 is a deficient number, since it is larger than the sum of its proper divisors (1123179717).

21340414243 is a wasteful number, since it uses less digits than its factorization.

21340414243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1123179716.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21340414243 its reverse (34241404312), we get a palindrome (55581818555).

The spelling of 21340414243 in words is "twenty-one billion, three hundred forty million, four hundred fourteen thousand, two hundred forty-three".