21104827 has 4 divisors (see below), whose sum is σ = 21114016. Its totient is φ = 21095640.

The previous prime is 21104819. The next prime is 21104843. The reversal of 21104827 is 72840112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21104827 - 2³ = 21104819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21104857) 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, 2293 + ... + 6889.

It is an arithmetic number, because the mean of its divisors is an integer number (5278504).

Almost surely, 2^21104827 is an apocalyptic number.

21104827 is a deficient number, since it is larger than the sum of its proper divisors (9189).

21104827 is an equidigital number, since it uses as much as digits as its factorization.

21104827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9188.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 21104827 is about 4593.9990204614. Note that the first 3 decimals coincide. The cubic root of 21104827 is about 276.3507189916.

Adding to 21104827 its reverse (72840112), we get a palindrome (93944939).

The spelling of 21104827 in words is "twenty-one million, one hundred four thousand, eight hundred twenty-seven".