404581687421 has 4 divisors (see below), whose sum is σ = 404768909244. Its totient is φ = 404394465600.

The previous prime is 404581687397. The next prime is 404581687429. The reversal of 404581687421 is 124786185404.

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 127816260196 + 276765427225 = 357514^2 + 526085^2 .

It is a cyclic number.

It is not a de Polignac number, because 404581687421 - 2¹⁸ = 404581425277 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 404581687421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404581687429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93607670 + ... + 93611991.

It is an arithmetic number, because the mean of its divisors is an integer number (101192227311).

Almost surely, 2^404581687421 is an apocalyptic number.

It is an amenable number.

404581687421 is a deficient number, since it is larger than the sum of its proper divisors (187221823).

404581687421 is a wasteful number, since it uses less digits than its factorization.

404581687421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187221822.

The product of its (nonzero) digits is 1720320, while the sum is 50.

The spelling of 404581687421 in words is "four hundred four billion, five hundred eighty-one million, six hundred eighty-seven thousand, four hundred twenty-one".