21431343 has 8 divisors (see below), whose sum is σ = 28627456. Its totient is φ = 14261400.

The previous prime is 21431341. The next prime is 21431353. The reversal of 21431343 is 34313412.

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

It is not a de Polignac number, because 21431343 - 2¹ = 21431341 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 (21431341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4543 + ... + 7968.

It is an arithmetic number, because the mean of its divisors is an integer number (3578432).

Almost surely, 2^21431343 is an apocalyptic number.

21431343 is a deficient number, since it is larger than the sum of its proper divisors (7196113).

21431343 is a wasteful number, since it uses less digits than its factorization.

21431343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13085.

The product of its digits is 864, while the sum is 21.

The square root of 21431343 is about 4629.3998531127. The cubic root of 21431343 is about 277.7685866411.

Adding to 21431343 its reverse (34313412), we get a palindrome (55744755).

It can be divided in two parts, 2143 and 1343, that added together give a triangular number (3486 = T₈₃).

The spelling of 21431343 in words is "twenty-one million, four hundred thirty-one thousand, three hundred forty-three".