21343081 has 4 divisors (see below), whose sum is σ = 21354112. Its totient is φ = 21332052.

The previous prime is 21343039. The next prime is 21343111. The reversal of 21343081 is 18034312.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21343081 - 2⁷ = 21342953 is a prime.

It is a super-2 number, since 2×21343081² = 911054213145122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21343481) 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 3 ways as a sum of consecutive naturals, for example, 1761 + ... + 6766.

It is an arithmetic number, because the mean of its divisors is an integer number (5338528).

Almost surely, 2^21343081 is an apocalyptic number.

It is an amenable number.

21343081 is a deficient number, since it is larger than the sum of its proper divisors (11031).

21343081 is an equidigital number, since it uses as much as digits as its factorization.

21343081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11030.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21343081 is about 4619.8572488769. The cubic root of 21343081 is about 277.3867448993.

Adding to 21343081 its reverse (18034312), we get a palindrome (39377393).

The spelling of 21343081 in words is "twenty-one million, three hundred forty-three thousand, eighty-one".