636403 has 2 divisors, whose sum is σ = 636404. Its totient is φ = 636402.

The previous prime is 636359. The next prime is 636407. The reversal of 636403 is 304636.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 636403 - 2⁹ = 635891 is a prime.

It is an Ulam number.

It is equal to p₅₁₈₂₆ and since 636403 and 51826 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (636407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318201 + 318202.

It is an arithmetic number, because the mean of its divisors is an integer number (318202).

2⁶³⁶⁴⁰³ is an apocalyptic number.

636403 is a deficient number, since it is larger than the sum of its proper divisors (1).

636403 is an equidigital number, since it uses as much as digits as its factorization.

636403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 22.

The square root of 636403 is about 797.7487073007. The cubic root of 636403 is about 86.0156362411.

The spelling of 636403 in words is "six hundred thirty-six thousand, four hundred three".