128631601181 has 2 divisors, whose sum is σ = 128631601182. Its totient is φ = 128631601180.

The previous prime is 128631601129. The next prime is 128631601201. The reversal of 128631601181 is 181106136821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126617835556 + 2013765625 = 355834^2 + 44875^2 .

It is an emirp because it is prime and its reverse (181106136821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128631601181 - 2⁶ = 128631601117 is a prime.

It is a super-2 number, since 2×128631601181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128631601381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64315800590 + 64315800591.

It is an arithmetic number, because the mean of its divisors is an integer number (64315800591).

Almost surely, 2^128631601181 is an apocalyptic number.

It is an amenable number.

128631601181 is a deficient number, since it is larger than the sum of its proper divisors (1).

128631601181 is an equidigital number, since it uses as much as digits as its factorization.

128631601181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 38.

The spelling of 128631601181 in words is "one hundred twenty-eight billion, six hundred thirty-one million, six hundred one thousand, one hundred eighty-one".