21243202135 has 32 divisors (see below), whose sum is σ = 26475724800. Its totient is φ = 16345764480.

The previous prime is 21243202133. The next prime is 21243202157. The reversal of 21243202135 is 53120234212.

It is not a de Polignac number, because 21243202135 - 2¹ = 21243202133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243202133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26653557 + ... + 26654353.

It is an arithmetic number, because the mean of its divisors is an integer number (827366400).

Almost surely, 2^21243202135 is an apocalyptic number.

21243202135 is a deficient number, since it is larger than the sum of its proper divisors (5232522665).

21243202135 is a wasteful number, since it uses less digits than its factorization.

21243202135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21243202135 its reverse (53120234212), we get a palindrome (74363436347).

The spelling of 21243202135 in words is "twenty-one billion, two hundred forty-three million, two hundred two thousand, one hundred thirty-five".