405997 has 2 divisors, whose sum is σ = 405998. Its totient is φ = 405996.

The previous prime is 405991. The next prime is 406013. The reversal of 405997 is 799504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 335241 + 70756 = 579^2 + 266^2 .

It is a cyclic number.

It is not a de Polignac number, because 405997 - 2³ = 405989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (405991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202998 + 202999.

It is an arithmetic number, because the mean of its divisors is an integer number (202999).

2⁴⁰⁵⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

405997 is a deficient number, since it is larger than the sum of its proper divisors (1).

405997 is an equidigital number, since it uses as much as digits as its factorization.

405997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11340, while the sum is 34.

The square root of 405997 is about 637.1789387605. The cubic root of 405997 is about 74.0470239225.

The spelling of 405997 in words is "four hundred five thousand, nine hundred ninety-seven".