21404011 has 4 divisors (see below), whose sum is σ = 21450312. Its totient is φ = 21357712.

The previous prime is 21403979. The next prime is 21404017. The reversal of 21404011 is 11040412.

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 21404011 - 2⁵ = 21403979 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21403982 and 21404000.

It is not an unprimeable number, because it can be changed into a prime (21404017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22450 + ... + 23383.

It is an arithmetic number, because the mean of its divisors is an integer number (5362578).

Almost surely, 2^21404011 is an apocalyptic number.

21404011 is a deficient number, since it is larger than the sum of its proper divisors (46301).

21404011 is an equidigital number, since it uses as much as digits as its factorization.

21404011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46300.

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

The square root of 21404011 is about 4626.4469088059. The cubic root of 21404011 is about 277.6504543536.

Adding to 21404011 its reverse (11040412), we get a palindrome (32444423).

The spelling of 21404011 in words is "twenty-one million, four hundred four thousand, eleven".