636544091 has 2 divisors, whose sum is σ = 636544092. Its totient is φ = 636544090.

The previous prime is 636544079. The next prime is 636544163. The reversal of 636544091 is 190445636.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 636544091 - 2¹⁴ = 636527707 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (636544291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318272045 + 318272046.

It is an arithmetic number, because the mean of its divisors is an integer number (318272046).

Almost surely, 2^636544091 is an apocalyptic number.

636544091 is a deficient number, since it is larger than the sum of its proper divisors (1).

636544091 is an equidigital number, since it uses as much as digits as its factorization.

636544091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 636544091 is about 25229.8254254761. The cubic root of 636544091 is about 860.2199234740.

The spelling of 636544091 in words is "six hundred thirty-six million, five hundred forty-four thousand, ninety-one".