21231132643 has 8 divisors (see below), whose sum is σ = 24270997760. Its totient is φ = 18192979080.

The previous prime is 21231132641. The next prime is 21231132661. The reversal of 21231132643 is 34623113212.

It is a happy number.

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 21231132643 - 2¹ = 21231132641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21231132641) 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, 401193 + ... + 451018.

It is an arithmetic number, because the mean of its divisors is an integer number (3033874720).

Almost surely, 2^21231132643 is an apocalyptic number.

21231132643 is a deficient number, since it is larger than the sum of its proper divisors (3039865117).

21231132643 is an equidigital number, since it uses as much as digits as its factorization.

21231132643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855777.

The product of its digits is 5184, while the sum is 28.

Adding to 21231132643 its reverse (34623113212), we get a palindrome (55854245855).

The spelling of 21231132643 in words is "twenty-one billion, two hundred thirty-one million, one hundred thirty-two thousand, six hundred forty-three".