21466811 has 4 divisors (see below), whose sum is σ = 21578232. Its totient is φ = 21355392.

The previous prime is 21466807. The next prime is 21466829. The reversal of 21466811 is 11866412.

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 21466811 - 2² = 21466807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21466831) 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, 55421 + ... + 55806.

It is an arithmetic number, because the mean of its divisors is an integer number (5394558).

Almost surely, 2^21466811 is an apocalyptic number.

21466811 is a deficient number, since it is larger than the sum of its proper divisors (111421).

21466811 is a wasteful number, since it uses less digits than its factorization.

21466811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111420.

The product of its digits is 2304, while the sum is 29.

The square root of 21466811 is about 4633.2290036216. The cubic root of 21466811 is about 277.9217340880.

The spelling of 21466811 in words is "twenty-one million, four hundred sixty-six thousand, eight hundred eleven".