405440393 has 2 divisors, whose sum is σ = 405440394. Its totient is φ = 405440392.

The previous prime is 405440323. The next prime is 405440401. The reversal of 405440393 is 393044504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357512464 + 47927929 = 18908^2 + 6923^2 .

It is a cyclic number.

It is not a de Polignac number, because 405440393 - 2⁸ = 405440137 is a prime.

It is not a weakly prime, because it can be changed into another prime (405440323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202720196 + 202720197.

It is an arithmetic number, because the mean of its divisors is an integer number (202720197).

Almost surely, 2^405440393 is an apocalyptic number.

It is an amenable number.

405440393 is a deficient number, since it is larger than the sum of its proper divisors (1).

405440393 is an equidigital number, since it uses as much as digits as its factorization.

405440393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 405440393 is about 20135.5504767066. The cubic root of 405440393 is about 740.1316986200.

Adding to 405440393 its reverse (393044504), we get a palindrome (798484897).

The spelling of 405440393 in words is "four hundred five million, four hundred forty thousand, three hundred ninety-three".