21131230343 has 4 divisors (see below), whose sum is σ = 21135638400. Its totient is φ = 21126822288.

The previous prime is 21131230303. The next prime is 21131230363. The reversal of 21131230343 is 34303213112.

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 21131230343 - 2¹² = 21131226247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131230303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2196830 + ... + 2206427.

It is an arithmetic number, because the mean of its divisors is an integer number (5283909600).

Almost surely, 2^21131230343 is an apocalyptic number.

21131230343 is a deficient number, since it is larger than the sum of its proper divisors (4408057).

21131230343 is an equidigital number, since it uses as much as digits as its factorization.

21131230343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4408056.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21131230343 its reverse (34303213112), we get a palindrome (55434443455).

The spelling of 21131230343 in words is "twenty-one billion, one hundred thirty-one million, two hundred thirty thousand, three hundred forty-three".