21013434231 has 8 divisors (see below), whose sum is σ = 28669491840. Its totient is φ = 13683166392.

The previous prime is 21013434209. The next prime is 21013434251. The reversal of 21013434231 is 13243431012.

It is a happy number.

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

It is not a de Polignac number, because 21013434231 - 2¹³ = 21013426039 is a prime.

It is a super-2 number, since 2×21013434231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013434251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81447291 + ... + 81447548.

It is an arithmetic number, because the mean of its divisors is an integer number (3583686480).

Almost surely, 2^21013434231 is an apocalyptic number.

21013434231 is a deficient number, since it is larger than the sum of its proper divisors (7656057609).

21013434231 is a wasteful number, since it uses less digits than its factorization.

21013434231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162894885.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21013434231 its reverse (13243431012), we get a palindrome (34256865243).

The spelling of 21013434231 in words is "twenty-one billion, thirteen million, four hundred thirty-four thousand, two hundred thirty-one".