21201204243 has 8 divisors (see below), whose sum is σ = 28269355968. Its totient is φ = 14133594344.

The previous prime is 21201204229. The next prime is 21201204259. The reversal of 21201204243 is 34240210212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21201204243 - 2⁸ = 21201203987 is a prime.

It is a super-2 number, since 2×21201204243² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21201204443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33105 + ... + 208562.

It is an arithmetic number, because the mean of its divisors is an integer number (3533669496).

Almost surely, 2^21201204243 is an apocalyptic number.

21201204243 is a deficient number, since it is larger than the sum of its proper divisors (7068151725).

21201204243 is a wasteful number, since it uses less digits than its factorization.

21201204243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270913.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21201204243 its reverse (34240210212), we get a palindrome (55441414455).

The spelling of 21201204243 in words is "twenty-one billion, two hundred one million, two hundred four thousand, two hundred forty-three".