1183801981 has 2 divisors, whose sum is σ = 1183801982. Its totient is φ = 1183801980.

The previous prime is 1183801963. The next prime is 1183801999. The reversal of 1183801981 is 1891083811.

It is a balanced prime because it is at equal distance from previous prime (1183801963) and next prime (1183801999).

It can be written as a sum of positive squares in only one way, i.e., 969325956 + 214476025 = 31134^2 + 14645^2 .

It is a cyclic number.

It is not a de Polignac number, because 1183801981 - 2¹³ = 1183793789 is a prime.

It is a super-3 number, since 3×1183801981³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1183801921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 591900990 + 591900991.

It is an arithmetic number, because the mean of its divisors is an integer number (591900991).

Almost surely, 2^1183801981 is an apocalyptic number.

It is an amenable number.

1183801981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1183801981 is an equidigital number, since it uses as much as digits as its factorization.

1183801981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 40.

The square root of 1183801981 is about 34406.4235427049. The cubic root of 1183801981 is about 1057.8555140067.

The spelling of 1183801981 in words is "one billion, one hundred eighty-three million, eight hundred one thousand, nine hundred eighty-one".