21342307 has 4 divisors (see below), whose sum is σ = 24391216. Its totient is φ = 18293400.

The previous prime is 21342287. The next prime is 21342311. The reversal of 21342307 is 70324312.

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 21342307 - 2⁷ = 21342179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21342337) 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, 1524444 + ... + 1524457.

It is an arithmetic number, because the mean of its divisors is an integer number (6097804).

Almost surely, 2^21342307 is an apocalyptic number.

21342307 is a deficient number, since it is larger than the sum of its proper divisors (3048909).

21342307 is an equidigital number, since it uses as much as digits as its factorization.

21342307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3048908.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 21342307 is about 4619.7734792953. The cubic root of 21342307 is about 277.3833917450.

Adding to 21342307 its reverse (70324312), we get a palindrome (91666619).

The spelling of 21342307 in words is "twenty-one million, three hundred forty-two thousand, three hundred seven".