21143789 has 4 divisors (see below), whose sum is σ = 22256640. Its totient is φ = 20030940.

The previous prime is 21143783. The next prime is 21143791. The reversal of 21143789 is 98734112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21143789 - 2⁸ = 21143533 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 (21143783) 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, 556397 + ... + 556434.

It is an arithmetic number, because the mean of its divisors is an integer number (5564160).

Almost surely, 2^21143789 is an apocalyptic number.

It is an amenable number.

21143789 is a deficient number, since it is larger than the sum of its proper divisors (1112851).

21143789 is a wasteful number, since it uses less digits than its factorization.

21143789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112850.

The product of its digits is 12096, while the sum is 35.

The square root of 21143789 is about 4598.2375971670. The cubic root of 21143789 is about 276.5206731238.

The spelling of 21143789 in words is "twenty-one million, one hundred forty-three thousand, seven hundred eighty-nine".