405405689 has 4 divisors (see below), whose sum is σ = 436590756. Its totient is φ = 374220624.

The previous prime is 405405683. The next prime is 405405757. The reversal of 405405689 is 986504504.

It is a happy number.

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 82664464 + 322741225 = 9092^2 + 17965^2 .

It is a cyclic number.

It is not a de Polignac number, because 405405689 - 2⁴ = 405405673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (405405683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15592514 + ... + 15592539.

It is an arithmetic number, because the mean of its divisors is an integer number (109147689).

Almost surely, 2^405405689 is an apocalyptic number.

It is an amenable number.

405405689 is a deficient number, since it is larger than the sum of its proper divisors (31185067).

405405689 is a wasteful number, since it uses less digits than its factorization.

405405689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31185066.

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 405405689 is about 20134.6886988600. The cubic root of 405405689 is about 740.1105806260.

The spelling of 405405689 in words is "four hundred five million, four hundred five thousand, six hundred eighty-nine".