1391186081 has 2 divisors, whose sum is σ = 1391186082. Its totient is φ = 1391186080.

The previous prime is 1391186077. The next prime is 1391186117. The reversal of 1391186081 is 1806811931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1177587856 + 213598225 = 34316^2 + 14615^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391186081 - 2² = 1391186077 is a prime.

It is a super-2 number, since 2×1391186081² = 3870797423936277122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1391186011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695593040 + 695593041.

It is an arithmetic number, because the mean of its divisors is an integer number (695593041).

Almost surely, 2^1391186081 is an apocalyptic number.

It is an amenable number.

1391186081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391186081 is an equidigital number, since it uses as much as digits as its factorization.

1391186081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 1391186081 is about 37298.6069579013. The cubic root of 1391186081 is about 1116.3363710830.

The spelling of 1391186081 in words is "one billion, three hundred ninety-one million, one hundred eighty-six thousand, eighty-one".