21241109 has 4 divisors (see below), whose sum is σ = 22490604. Its totient is φ = 19991616.

The previous prime is 21241093. The next prime is 21241123. The reversal of 21241109 is 90114212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8439025 + 12802084 = 2905^2 + 3578^2 .

It is a cyclic number.

It is not a de Polignac number, because 21241109 - 2⁴ = 21241093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 624722 + ... + 624755.

It is an arithmetic number, because the mean of its divisors is an integer number (5622651).

Almost surely, 2^21241109 is an apocalyptic number.

It is an amenable number.

21241109 is a deficient number, since it is larger than the sum of its proper divisors (1249495).

21241109 is a wasteful number, since it uses less digits than its factorization.

21241109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249494.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 21241109 is about 4608.8077634026. The cubic root of 21241109 is about 276.9442775653.

The spelling of 21241109 in words is "twenty-one million, two hundred forty-one thousand, one hundred nine".