21432143 has 8 divisors (see below), whose sum is σ = 21894528. Its totient is φ = 20974464.

The previous prime is 21432107. The next prime is 21432157. The reversal of 21432143 is 34123412.

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 21432143 - 2⁶ = 21432079 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8930 + ... + 11072.

It is an arithmetic number, because the mean of its divisors is an integer number (2736816).

Almost surely, 2^21432143 is an apocalyptic number.

21432143 is a deficient number, since it is larger than the sum of its proper divisors (462385).

21432143 is a wasteful number, since it uses less digits than its factorization.

21432143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2353.

The product of its digits is 576, while the sum is 20.

The square root of 21432143 is about 4629.4862565948. The cubic root of 21432143 is about 277.7720428268.

Adding to 21432143 its reverse (34123412), we get a palindrome (55555555).

The spelling of 21432143 in words is "twenty-one million, four hundred thirty-two thousand, one hundred forty-three".