404640293 has 2 divisors, whose sum is σ = 404640294. Its totient is φ = 404640292.

The previous prime is 404640227. The next prime is 404640317. The reversal of 404640293 is 392046404.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 247338529 + 157301764 = 15727^2 + 12542^2 .

It is a cyclic number.

It is not a de Polignac number, because 404640293 - 2¹⁰ = 404639269 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404640493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202320146 + 202320147.

It is an arithmetic number, because the mean of its divisors is an integer number (202320147).

Almost surely, 2^404640293 is an apocalyptic number.

It is an amenable number.

404640293 is a deficient number, since it is larger than the sum of its proper divisors (1).

404640293 is an equidigital number, since it uses as much as digits as its factorization.

404640293 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 404640293 is about 20115.6728199680. The cubic root of 404640293 is about 739.6445169878.

Adding to 404640293 its reverse (392046404), we get a palindrome (796686697).

The spelling of 404640293 in words is "four hundred four million, six hundred forty thousand, two hundred ninety-three".