404016391 has 2 divisors, whose sum is σ = 404016392. Its totient is φ = 404016390.

The previous prime is 404016343. The next prime is 404016401. The reversal of 404016391 is 193610404.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 404016391 - 2¹⁷ = 403885319 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404016311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202008195 + 202008196.

It is an arithmetic number, because the mean of its divisors is an integer number (202008196).

Almost surely, 2^404016391 is an apocalyptic number.

404016391 is a deficient number, since it is larger than the sum of its proper divisors (1).

404016391 is an equidigital number, since it uses as much as digits as its factorization.

404016391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 404016391 is about 20100.1589794708. The cubic root of 404016391 is about 739.2641766560.

Adding to 404016391 its reverse (193610404), we get a palindrome (597626795).

The spelling of 404016391 in words is "four hundred four million, sixteen thousand, three hundred ninety-one".