21202432243 has 4 divisors (see below), whose sum is σ = 21396950080. Its totient is φ = 21007914408.

The previous prime is 21202432241. The next prime is 21202432267. The reversal of 21202432243 is 34223420212.

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 21202432243 - 2¹ = 21202432241 is a prime.

It is a super-2 number, since 2×21202432243² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202432241) 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, 97258755 + ... + 97258972.

It is an arithmetic number, because the mean of its divisors is an integer number (5349237520).

Almost surely, 2^21202432243 is an apocalyptic number.

21202432243 is a deficient number, since it is larger than the sum of its proper divisors (194517837).

21202432243 is a wasteful number, since it uses less digits than its factorization.

21202432243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194517836.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21202432243 its reverse (34223420212), we get a palindrome (55425852455).

The spelling of 21202432243 in words is "twenty-one billion, two hundred two million, four hundred thirty-two thousand, two hundred forty-three".