405503993 has 2 divisors, whose sum is σ = 405503994. Its totient is φ = 405503992.

The previous prime is 405503957. The next prime is 405504019. The reversal of 405503993 is 399305504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 347561449 + 57942544 = 18643^2 + 7612^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405503993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (405503953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202751996 + 202751997.

It is an arithmetic number, because the mean of its divisors is an integer number (202751997).

Almost surely, 2^405503993 is an apocalyptic number.

It is an amenable number.

405503993 is a deficient number, since it is larger than the sum of its proper divisors (1).

405503993 is an equidigital number, since it uses as much as digits as its factorization.

405503993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72900, while the sum is 38.

The square root of 405503993 is about 20137.1297110586. The cubic root of 405503993 is about 740.1703972102.

The spelling of 405503993 in words is "four hundred five million, five hundred three thousand, nine hundred ninety-three".