405688889 has 2 divisors, whose sum is σ = 405688890. Its totient is φ = 405688888.

The previous prime is 405688841. The next prime is 405688949. The reversal of 405688889 is 988886504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 404331664 + 1357225 = 20108^2 + 1165^2 .

It is a cyclic number.

It is not a de Polignac number, because 405688889 - 2¹² = 405684793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (405628889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202844444 + 202844445.

It is an arithmetic number, because the mean of its divisors is an integer number (202844445).

Almost surely, 2^405688889 is an apocalyptic number.

It is an amenable number.

405688889 is a deficient number, since it is larger than the sum of its proper divisors (1).

405688889 is an equidigital number, since it uses as much as digits as its factorization.

405688889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4423680, while the sum is 56.

The square root of 405688889 is about 20141.7201102587. The cubic root of 405688889 is about 740.2828776075.

The spelling of 405688889 in words is "four hundred five million, six hundred eighty-eight thousand, eight hundred eighty-nine".