4099921 has 16 divisors (see below), whose sum is σ = 4904064. Its totient is φ = 3354624.

The previous prime is 4099903. The next prime is 4099943. The reversal of 4099921 is 1299904.

It is not a de Polignac number, because 4099921 - 2⁵ = 4099889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4099961) 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 15 ways as a sum of consecutive naturals, for example, 15825 + ... + 16081.

It is an arithmetic number, because the mean of its divisors is an integer number (306504).

Almost surely, 2^4099921 is an apocalyptic number.

It is an amenable number.

4099921 is a deficient number, since it is larger than the sum of its proper divisors (804143).

4099921 is a wasteful number, since it uses less digits than its factorization.

4099921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 4099921 is about 2024.8261653782. The cubic root of 4099921 is about 160.0510384050.

The spelling of 4099921 in words is "four million, ninety-nine thousand, nine hundred twenty-one".