21214211 has 4 divisors (see below), whose sum is σ = 22136592. Its totient is φ = 20291832.

The previous prime is 21214187. The next prime is 21214229. The reversal of 21214211 is 11241212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21214211 - 2¹⁰ = 21213187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21214231) 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, 461156 + ... + 461201.

It is an arithmetic number, because the mean of its divisors is an integer number (5534148).

Almost surely, 2^21214211 is an apocalyptic number.

21214211 is a deficient number, since it is larger than the sum of its proper divisors (922381).

21214211 is an equidigital number, since it uses as much as digits as its factorization.

21214211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 922380.

The product of its digits is 32, while the sum is 14.

The square root of 21214211 is about 4605.8887307446. Note that the first 3 decimals coincide. The cubic root of 21214211 is about 276.8273283394.

Adding to 21214211 its reverse (11241212), we get a palindrome (32455423).

The spelling of 21214211 in words is "twenty-one million, two hundred fourteen thousand, two hundred eleven".