21104819 has 2 divisors, whose sum is σ = 21104820. Its totient is φ = 21104818.

The previous prime is 21104773. The next prime is 21104843. The reversal of 21104819 is 91840112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21104819 - 2⁸ = 21104563 is a prime.

It is a super-2 number, since 2×21104819² = 890826770045522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p_1336175 and since 21104819 and 1336175 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21104849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10552409 + 10552410.

It is an arithmetic number, because the mean of its divisors is an integer number (10552410).

Almost surely, 2^21104819 is an apocalyptic number.

21104819 is a deficient number, since it is larger than the sum of its proper divisors (1).

21104819 is an equidigital number, since it uses as much as digits as its factorization.

21104819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 21104819 is about 4593.9981497602. The cubic root of 21104819 is about 276.3506840737.

The spelling of 21104819 in words is "twenty-one million, one hundred four thousand, eight hundred nineteen".