404100021 has 16 divisors (see below), whose sum is σ = 581227136. Its totient is φ = 248256576.

The previous prime is 404100019. The next prime is 404100029. The reversal of 404100021 is 120001404.

It is not a de Polignac number, because 404100021 - 2¹ = 404100019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404100029) 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, 15456 + ... + 32358.

It is an arithmetic number, because the mean of its divisors is an integer number (36326696).

Almost surely, 2^404100021 is an apocalyptic number.

It is an amenable number.

404100021 is a deficient number, since it is larger than the sum of its proper divisors (177127115).

404100021 is a wasteful number, since it uses less digits than its factorization.

404100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17532.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 404100021 is about 20102.2392036310. The cubic root of 404100021 is about 739.3151815155.

Adding to 404100021 its reverse (120001404), we get a palindrome (524101425).

The spelling of 404100021 in words is "four hundred four million, one hundred thousand, twenty-one".