636493508641 has 2 divisors, whose sum is σ = 636493508642. Its totient is φ = 636493508640.

The previous prime is 636493508639. The next prime is 636493508663. The reversal of 636493508641 is 146805394636.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 443161815616 + 193331693025 = 665704^2 + 439695^2 .

It is a cyclic number.

It is not a de Polignac number, because 636493508641 - 2¹ = 636493508639 is a prime.

Together with 636493508639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (636493508341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318246754320 + 318246754321.

It is an arithmetic number, because the mean of its divisors is an integer number (318246754321).

Almost surely, 2^636493508641 is an apocalyptic number.

It is an amenable number.

636493508641 is a deficient number, since it is larger than the sum of its proper divisors (1).

636493508641 is an equidigital number, since it uses as much as digits as its factorization.

636493508641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11197440, while the sum is 55.

The spelling of 636493508641 in words is "six hundred thirty-six billion, four hundred ninety-three million, five hundred eight thousand, six hundred forty-one".