400253591 has 2 divisors, whose sum is σ = 400253592. Its totient is φ = 400253590.

The previous prime is 400253549. The next prime is 400253647. The reversal of 400253591 is 195352004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400253591 - 2¹⁸ = 399991447 is a prime.

It is equal to p_21349127 and since 400253591 and 21349127 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400253501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200126795 + 200126796.

It is an arithmetic number, because the mean of its divisors is an integer number (200126796).

Almost surely, 2^400253591 is an apocalyptic number.

400253591 is a deficient number, since it is larger than the sum of its proper divisors (1).

400253591 is an equidigital number, since it uses as much as digits as its factorization.

400253591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 400253591 is about 20006.3387704997. The cubic root of 400253591 is about 736.9619730402.

The spelling of 400253591 in words is "four hundred million, two hundred fifty-three thousand, five hundred ninety-one".