104209921 has 4 divisors (see below), whose sum is σ = 104251392. Its totient is φ = 104168452.

The previous prime is 104209901. The next prime is 104209943. The reversal of 104209921 is 129902401.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 104209921 - 2¹⁵ = 104177153 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 104209921.

It is not an unprimeable number, because it can be changed into a prime (104209901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16705 + ... + 22078.

It is an arithmetic number, because the mean of its divisors is an integer number (26062848).

Almost surely, 2^104209921 is an apocalyptic number.

It is an amenable number.

104209921 is a deficient number, since it is larger than the sum of its proper divisors (41471).

104209921 is an equidigital number, since it uses as much as digits as its factorization.

104209921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41470.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 104209921 is about 10208.3260625824. The cubic root of 104209921 is about 470.5831316459.

The spelling of 104209921 in words is "one hundred four million, two hundred nine thousand, nine hundred twenty-one".