1188161281 has 2 divisors, whose sum is σ = 1188161282. Its totient is φ = 1188161280.

The previous prime is 1188161267. The next prime is 1188161309. The reversal of 1188161281 is 1821618811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 813390400 + 374770881 = 28520^2 + 19359^2 .

It is a cyclic number.

It is not a de Polignac number, because 1188161281 - 2¹¹ = 1188159233 is a prime.

It is a super-2 number, since 2×1188161281² = 2823454459335121922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1188161281.

It is not a weakly prime, because it can be changed into another prime (1188161201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 594080640 + 594080641.

It is an arithmetic number, because the mean of its divisors is an integer number (594080641).

Almost surely, 2^1188161281 is an apocalyptic number.

It is an amenable number.

1188161281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1188161281 is an equidigital number, since it uses as much as digits as its factorization.

1188161281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6144, while the sum is 37.

The square root of 1188161281 is about 34469.7154180304. The cubic root of 1188161281 is about 1059.1524258795.

The spelling of 1188161281 in words is "one billion, one hundred eighty-eight million, one hundred sixty-one thousand, two hundred eighty-one".