21341909 has 8 divisors (see below), whose sum is σ = 21645312. Its totient is φ = 21040560.

The previous prime is 21341897. The next prime is 21341911. The reversal of 21341909 is 90914312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21341909 - 2²⁰ = 20293333 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343909) 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 7 ways as a sum of consecutive naturals, for example, 39179 + ... + 39719.

It is an arithmetic number, because the mean of its divisors is an integer number (2705664).

Almost surely, 2^21341909 is an apocalyptic number.

It is an amenable number.

21341909 is a deficient number, since it is larger than the sum of its proper divisors (303403).

21341909 is a wasteful number, since it uses less digits than its factorization.

21341909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 21341909 is about 4619.7304033894. The cubic root of 21341909 is about 277.3816674816.

The spelling of 21341909 in words is "twenty-one million, three hundred forty-one thousand, nine hundred nine".