1166681381 has 2 divisors, whose sum is σ = 1166681382. Its totient is φ = 1166681380.

The previous prime is 1166681353. The next prime is 1166681387. The reversal of 1166681381 is 1831866611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1034201281 + 132480100 = 32159^2 + 11510^2 .

It is an emirp because it is prime and its reverse (1831866611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1166681381 - 2⁶ = 1166681317 is a prime.

It is a super-2 number, since 2×1166681381² = 2722290889544134322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1166681387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583340690 + 583340691.

It is an arithmetic number, because the mean of its divisors is an integer number (583340691).

Almost surely, 2^1166681381 is an apocalyptic number.

It is an amenable number.

1166681381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1166681381 is an equidigital number, since it uses as much as digits as its factorization.

1166681381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 41.

The square root of 1166681381 is about 34156.7179483041. The cubic root of 1166681381 is about 1052.7310253537.

The spelling of 1166681381 in words is "one billion, one hundred sixty-six million, six hundred eighty-one thousand, three hundred eighty-one".