636428213 has 2 divisors, whose sum is σ = 636428214. Its totient is φ = 636428212.

The previous prime is 636428209. The next prime is 636428227. The reversal of 636428213 is 312824636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 636199729 + 228484 = 25223^2 + 478^2 .

It is a cyclic number.

It is not a de Polignac number, because 636428213 - 2² = 636428209 is a prime.

It is a super-3 number, since 3×636428213³ (a number of 27 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636428413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318214106 + 318214107.

It is an arithmetic number, because the mean of its divisors is an integer number (318214107).

Almost surely, 2^636428213 is an apocalyptic number.

It is an amenable number.

636428213 is a deficient number, since it is larger than the sum of its proper divisors (1).

636428213 is an equidigital number, since it uses as much as digits as its factorization.

636428213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 35.

The square root of 636428213 is about 25227.5288722459. The cubic root of 636428213 is about 860.1677214795.

The spelling of 636428213 in words is "six hundred thirty-six million, four hundred twenty-eight thousand, two hundred thirteen".