21343805 has 16 divisors (see below), whose sum is σ = 29393280. Its totient is φ = 14574912.

The previous prime is 21343801. The next prime is 21343831. The reversal of 21343805 is 50834312.

It is a cyclic number.

It is not a de Polignac number, because 21343805 - 2² = 21343801 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8282 + ... + 10548.

It is an arithmetic number, because the mean of its divisors is an integer number (1837080).

Almost surely, 2^21343805 is an apocalyptic number.

It is an amenable number.

21343805 is a deficient number, since it is larger than the sum of its proper divisors (8049475).

21343805 is a wasteful number, since it uses less digits than its factorization.

21343805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2548.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21343805 is about 4619.9356056118. The cubic root of 21343805 is about 277.3898813683.

The spelling of 21343805 in words is "twenty-one million, three hundred forty-three thousand, eight hundred five".