1391081 has 2 divisors, whose sum is σ = 1391082. Its totient is φ = 1391080.

The previous prime is 1391057. The next prime is 1391083. The reversal of 1391081 is 1801931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1357225 + 33856 = 1165^2 + 184^2 .

It is an emirp because it is prime and its reverse (1801931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1391081 - 2¹⁴ = 1374697 is a prime.

It is a super-2 number, since 2×1391081² = 3870212697122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1391083, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1391083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695540 + 695541.

It is an arithmetic number, because the mean of its divisors is an integer number (695541).

2^1391081 is an apocalyptic number.

It is an amenable number.

1391081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391081 is an equidigital number, since it uses as much as digits as its factorization.

1391081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 1391081 is about 1179.4409692732. The cubic root of 1391081 is about 111.6308263485.

The spelling of 1391081 in words is "one million, three hundred ninety-one thousand, eighty-one".