405981593 has 2 divisors, whose sum is σ = 405981594. Its totient is φ = 405981592.

The previous prime is 405981581. The next prime is 405981601. The reversal of 405981593 is 395189504.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393506569 + 12475024 = 19837^2 + 3532^2 .

It is a cyclic number.

It is not a de Polignac number, because 405981593 - 2⁶ = 405981529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (405981523) 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, 202990796 + 202990797.

It is an arithmetic number, because the mean of its divisors is an integer number (202990797).

Almost surely, 2^405981593 is an apocalyptic number.

It is an amenable number.

405981593 is a deficient number, since it is larger than the sum of its proper divisors (1).

405981593 is an equidigital number, since it uses as much as digits as its factorization.

405981593 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 194400, while the sum is 44.

The square root of 405981593 is about 20148.9849123970. The cubic root of 405981593 is about 740.4608725142.

The spelling of 405981593 in words is "four hundred five million, nine hundred eighty-one thousand, five hundred ninety-three".