404131661 has 4 divisors (see below), whose sum is σ = 404172000. Its totient is φ = 404091324.

The previous prime is 404131639. The next prime is 404131669. The reversal of 404131661 is 166131404.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 404131661 - 2¹⁸ = 403869517 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 404131661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (404131669) 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, 7640 + ... + 29438.

It is an arithmetic number, because the mean of its divisors is an integer number (101043000).

Almost surely, 2^404131661 is an apocalyptic number.

It is an amenable number.

404131661 is a deficient number, since it is larger than the sum of its proper divisors (40339).

404131661 is a wasteful number, since it uses less digits than its factorization.

404131661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40338.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 404131661 is about 20103.0261652319. The cubic root of 404131661 is about 739.3344765090.

The spelling of 404131661 in words is "four hundred four million, one hundred thirty-one thousand, six hundred sixty-one".