1391086381 has 2 divisors, whose sum is σ = 1391086382. Its totient is φ = 1391086380.

The previous prime is 1391086363. The next prime is 1391086393. The reversal of 1391086381 is 1836801931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1068309225 + 322777156 = 32685^2 + 17966^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391086381 - 2¹⁵ = 1391053613 is a prime.

It is a super-2 number, since 2×1391086381² = 3870242638807354322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1391086481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695543190 + 695543191.

It is an arithmetic number, because the mean of its divisors is an integer number (695543191).

Almost surely, 2^1391086381 is an apocalyptic number.

It is an amenable number.

1391086381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391086381 is an equidigital number, since it uses as much as digits as its factorization.

1391086381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 1391086381 is about 37297.2704229143. The cubic root of 1391086381 is about 1116.3097028569.

The spelling of 1391086381 in words is "one billion, three hundred ninety-one million, eighty-six thousand, three hundred eighty-one".