21113143 has 4 divisors (see below), whose sum is σ = 21171040. Its totient is φ = 21055248.

The previous prime is 21113119. The next prime is 21113153. The reversal of 21113143 is 34131112.

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 21113143 - 2⁵ = 21113111 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 (21113153) 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 3 ways as a sum of consecutive naturals, for example, 28398 + ... + 29131.

It is an arithmetic number, because the mean of its divisors is an integer number (5292760).

Almost surely, 2^21113143 is an apocalyptic number.

21113143 is a deficient number, since it is larger than the sum of its proper divisors (57897).

21113143 is an equidigital number, since it uses as much as digits as its factorization.

21113143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57896.

The product of its digits is 72, while the sum is 16.

The square root of 21113143 is about 4594.9040251130. The cubic root of 21113143 is about 276.3870113336.

Adding to 21113143 its reverse (34131112), we get a palindrome (55244255).

The spelling of 21113143 in words is "twenty-one million, one hundred thirteen thousand, one hundred forty-three".