21084411 has 4 divisors (see below), whose sum is σ = 28112552. Its totient is φ = 14056272.

The previous prime is 21084397. The next prime is 21084419. The reversal of 21084411 is 11448012.

It is a happy number.

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

It is not a de Polignac number, because 21084411 - 2⁵ = 21084379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21084419) 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, 3514066 + ... + 3514071.

It is an arithmetic number, because the mean of its divisors is an integer number (7028138).

Almost surely, 2^21084411 is an apocalyptic number.

21084411 is a deficient number, since it is larger than the sum of its proper divisors (7028141).

21084411 is an equidigital number, since it uses as much as digits as its factorization.

21084411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7028140.

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 21084411 is about 4591.7764536179. The cubic root of 21084411 is about 276.2615798808.

The spelling of 21084411 in words is "twenty-one million, eighty-four thousand, four hundred eleven".