404609215921 has 45 divisors (see below), whose sum is σ = 450556603869. Its totient is φ = 363334036800.

The previous prime is 404609215919. The next prime is 404609215931. The reversal of 404609215921 is 129512906404.

The square root of 404609215921 is 636089.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 125571718321 + 279037497600 = 354361^2 + 528240^2 .

It is not a de Polignac number, because 404609215921 - 2¹ = 404609215919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (404609215931) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 5698721316 + ... + 5698721386.

Almost surely, 2^404609215921 is an apocalyptic number.

404609215921 is the 636089-th square number.

404609215921 is the 318045-th centered octagonal number.

It is an amenable number.

404609215921 is a deficient number, since it is larger than the sum of its proper divisors (45947387948).

404609215921 is an frugal number, since it uses more digits than its factorization.

404609215921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 43.

The spelling of 404609215921 in words is "four hundred four billion, six hundred nine million, two hundred fifteen thousand, nine hundred twenty-one".