21243000240443 has 4 divisors (see below), whose sum is σ = 21449242961328. Its totient is φ = 21036757519560.

The previous prime is 21243000240433. The next prime is 21243000240457. The reversal of 21243000240443 is 34404200034212.

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 21243000240443 - 2¹² = 21243000236347 is a prime.

It is a super-2 number, since 2×21243000240443² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243000240433) 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, 103121360288 + ... + 103121360493.

It is an arithmetic number, because the mean of its divisors is an integer number (5362310740332).

Almost surely, 2^{21243000240443} is an apocalyptic number.

21243000240443 is a deficient number, since it is larger than the sum of its proper divisors (206242720885).

21243000240443 is a wasteful number, since it uses less digits than its factorization.

21243000240443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206242720884.

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 21243000240443 its reverse (34404200034212), we get a palindrome (55647200274655).

The spelling of 21243000240443 in words is "twenty-one trillion, two hundred forty-three billion, two hundred forty thousand, four hundred forty-three".