404527721 has 4 divisors (see below), whose sum is σ = 435645252. Its totient is φ = 373410192.

The previous prime is 404527693. The next prime is 404527741. The reversal of 404527721 is 127725404.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124434025 + 280093696 = 11155^2 + 16736^2 .

It is a cyclic number.

It is not a de Polignac number, because 404527721 - 2¹⁸ = 404265577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (404527741) 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 3 ways as a sum of consecutive naturals, for example, 15558746 + ... + 15558771.

It is an arithmetic number, because the mean of its divisors is an integer number (108911313).

Almost surely, 2^404527721 is an apocalyptic number.

It is an amenable number.

404527721 is a deficient number, since it is larger than the sum of its proper divisors (31117531).

404527721 is a wasteful number, since it uses less digits than its factorization.

404527721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31117530.

The product of its (nonzero) digits is 15680, while the sum is 32.

The square root of 404527721 is about 20112.8745086325. The cubic root of 404527721 is about 739.5759202724.

The spelling of 404527721 in words is "four hundred four million, five hundred twenty-seven thousand, seven hundred twenty-one".