400544393 has 2 divisors, whose sum is σ = 400544394. Its totient is φ = 400544392.

The previous prime is 400544359. The next prime is 400544401. The reversal of 400544393 is 393445004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 225961024 + 174583369 = 15032^2 + 13213^2 .

It is a cyclic number.

It is not a de Polignac number, because 400544393 - 2⁶ = 400544329 is a prime.

It is not a weakly prime, because it can be changed into another prime (400544993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200272196 + 200272197.

It is an arithmetic number, because the mean of its divisors is an integer number (200272197).

Almost surely, 2^400544393 is an apocalyptic number.

It is an amenable number.

400544393 is a deficient number, since it is larger than the sum of its proper divisors (1).

400544393 is an equidigital number, since it uses as much as digits as its factorization.

400544393 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 400544393 is about 20013.6051974650. The cubic root of 400544393 is about 737.1404083618.

Adding to 400544393 its reverse (393445004), we get a palindrome (793989397).

The spelling of 400544393 in words is "four hundred million, five hundred forty-four thousand, three hundred ninety-three".