21343273 has 6 divisors (see below), whose sum is σ = 24827946. Its totient is φ = 18294192.

The previous prime is 21343261. The next prime is 21343307. The reversal of 21343273 is 37234312.

It can be written as a sum of positive squares in only one way, i.e., 21279769 + 63504 = 4613^2 + 252^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21343273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21343243) 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 5 ways as a sum of consecutive naturals, for example, 217740 + ... + 217837.

It is an arithmetic number, because the mean of its divisors is an integer number (4137991).

Almost surely, 2^21343273 is an apocalyptic number.

It is an amenable number.

21343273 is a deficient number, since it is larger than the sum of its proper divisors (3484673).

21343273 is an equidigital number, since it uses as much as digits as its factorization.

21343273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435591 (or 435584 counting only the distinct ones).

The product of its digits is 3024, while the sum is 25.

The square root of 21343273 is about 4619.8780286930. The cubic root of 21343273 is about 277.3875766770.

Adding to 21343273 its reverse (37234312), we get a palindrome (58577585).

The spelling of 21343273 in words is "twenty-one million, three hundred forty-three thousand, two hundred seventy-three".