1189966861 has 2 divisors, whose sum is σ = 1189966862. Its totient is φ = 1189966860.

The previous prime is 1189966859. The next prime is 1189966873. The reversal of 1189966861 is 1686699811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1174364361 + 15602500 = 34269^2 + 3950^2 .

It is a cyclic number.

It is not a de Polignac number, because 1189966861 - 2¹ = 1189966859 is a prime.

It is a super-2 number, since 2×1189966861² = 2832042260556386642, which contains 22 as substring.

Together with 1189966859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1189966891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 594983430 + 594983431.

It is an arithmetic number, because the mean of its divisors is an integer number (594983431).

Almost surely, 2^1189966861 is an apocalyptic number.

It is an amenable number.

1189966861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1189966861 is an equidigital number, since it uses as much as digits as its factorization.

1189966861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 55.

The square root of 1189966861 is about 34495.8962921679. The cubic root of 1189966861 is about 1059.6886652412.

The spelling of 1189966861 in words is "one billion, one hundred eighty-nine million, nine hundred sixty-six thousand, eight hundred sixty-one".