405866 has 4 divisors (see below), whose sum is σ = 608802. Its totient is φ = 202932.

The previous prime is 405863. The next prime is 405869. The reversal of 405866 is 668504.

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

It is an interprime number because it is at equal distance from previous prime (405863) and next prime (405869).

It can be written as a sum of positive squares in only one way, i.e., 279841 + 126025 = 529^2 + 355^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405866.

It is not an unprimeable number, because it can be changed into a prime (405863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101465 + ... + 101468.

2⁴⁰⁵⁸⁶⁶ is an apocalyptic number.

405866 is a deficient number, since it is larger than the sum of its proper divisors (202936).

405866 is a wasteful number, since it uses less digits than its factorization.

405866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202935.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 405866 is about 637.0761335979. The cubic root of 405866 is about 74.0390590002.

The spelling of 405866 in words is "four hundred five thousand, eight hundred sixty-six".