21042211 has 8 divisors (see below), whose sum is σ = 21839744. Its totient is φ = 20252160.

The previous prime is 21042193. The next prime is 21042223. The reversal of 21042211 is 11224012.

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 21042211 - 2²³ = 12653603 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21042191 and 21042200.

It is not an unprimeable number, because it can be changed into a prime (21042251) 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, 4225 + ... + 7741.

It is an arithmetic number, because the mean of its divisors is an integer number (2729968).

Almost surely, 2^21042211 is an apocalyptic number.

21042211 is a deficient number, since it is larger than the sum of its proper divisors (797533).

21042211 is a wasteful number, since it uses less digits than its factorization.

21042211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3741.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21042211 is about 4587.1789805936. The cubic root of 21042211 is about 276.0771462213.

Adding to 21042211 its reverse (11224012), we get a palindrome (32266223).

The spelling of 21042211 in words is "twenty-one million, forty-two thousand, two hundred eleven".