405644 has 6 divisors (see below), whose sum is σ = 709884. Its totient is φ = 202820.

The previous prime is 405641. The next prime is 405659. The reversal of 405644 is 446504.

It is a happy number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405644.

It is not an unprimeable number, because it can be changed into a prime (405641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50702 + ... + 50709.

It is an arithmetic number, because the mean of its divisors is an integer number (118314).

2⁴⁰⁵⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

405644 is a deficient number, since it is larger than the sum of its proper divisors (304240).

405644 is a wasteful number, since it uses less digits than its factorization.

405644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101415 (or 101413 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 405644 is about 636.9018762729. The cubic root of 405644 is about 74.0255572789.

The spelling of 405644 in words is "four hundred five thousand, six hundred forty-four".