21049211 has 4 divisors (see below), whose sum is σ = 21210024. Its totient is φ = 20888400.

The previous prime is 21049201. The next prime is 21049219. The reversal of 21049211 is 11294012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21049211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21049219) 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, 80210 + ... + 80471.

It is an arithmetic number, because the mean of its divisors is an integer number (5302506).

Almost surely, 2^21049211 is an apocalyptic number.

21049211 is a deficient number, since it is larger than the sum of its proper divisors (160813).

21049211 is a wasteful number, since it uses less digits than its factorization.

21049211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160812.

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

The square root of 21049211 is about 4587.9419133202. The cubic root of 21049211 is about 276.1077565307.

The spelling of 21049211 in words is "twenty-one million, forty-nine thousand, two hundred eleven".