21322143 has 8 divisors (see below), whose sum is σ = 31588400. Its totient is φ = 14214744.

The previous prime is 21322139. The next prime is 21322181. The reversal of 21322143 is 34122312.

It is not a de Polignac number, because 21322143 - 2² = 21322139 is a prime.

It is a super-2 number, since 2×21322143² = 909267564224898, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21322043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394828 + ... + 394881.

It is an arithmetic number, because the mean of its divisors is an integer number (3948550).

Almost surely, 2^21322143 is an apocalyptic number.

21322143 is a deficient number, since it is larger than the sum of its proper divisors (10266257).

21322143 is an equidigital number, since it uses as much as digits as its factorization.

21322143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789718 (or 789712 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 21322143 is about 4617.5906054998. The cubic root of 21322143 is about 277.2960078601.

Adding to 21322143 its reverse (34122312), we get a palindrome (55444455).

The spelling of 21322143 in words is "twenty-one million, three hundred twenty-two thousand, one hundred forty-three".