21141809 has 8 divisors (see below), whose sum is σ = 22982400. Its totient is φ = 19331856.

The previous prime is 21141803. The next prime is 21141821. The reversal of 21141809 is 90814112.

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 21141809 - 2⁴ = 21141793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21141803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6209 + ... + 8990.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^21141809 is an apocalyptic number.

It is an amenable number.

21141809 is a deficient number, since it is larger than the sum of its proper divisors (1840591).

21141809 is a wasteful number, since it uses less digits than its factorization.

21141809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15319.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 21141809 is about 4598.0222922470. The cubic root of 21141809 is about 276.5120413056.

The spelling of 21141809 in words is "twenty-one million, one hundred forty-one thousand, eight hundred nine".