636120427181 has 2 divisors, whose sum is σ = 636120427182. Its totient is φ = 636120427180.

The previous prime is 636120427153. The next prime is 636120427193. The reversal of 636120427181 is 181724021636.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 470987101225 + 165133325956 = 686285^2 + 406366^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-636120427181 is a prime.

It is a super-2 number, since 2×636120427181² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636120429181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318060213590 + 318060213591.

It is an arithmetic number, because the mean of its divisors is an integer number (318060213591).

Almost surely, 2^636120427181 is an apocalyptic number.

It is an amenable number.

636120427181 is a deficient number, since it is larger than the sum of its proper divisors (1).

636120427181 is an equidigital number, since it uses as much as digits as its factorization.

636120427181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 636120427181 in words is "six hundred thirty-six billion, one hundred twenty million, four hundred twenty-seven thousand, one hundred eighty-one".