1391667281 has 2 divisors, whose sum is σ = 1391667282. Its totient is φ = 1391667280.

The previous prime is 1391667259. The next prime is 1391667287. The reversal of 1391667281 is 1827661931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1361241025 + 30426256 = 36895^2 + 5516^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1391667281 is a prime.

It is a super-2 number, since 2×1391667281² = 3873475642011865922, 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 (1391667287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695833640 + 695833641.

It is an arithmetic number, because the mean of its divisors is an integer number (695833641).

Almost surely, 2^1391667281 is an apocalyptic number.

It is an amenable number.

1391667281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391667281 is an equidigital number, since it uses as much as digits as its factorization.

1391667281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 1391667281 is about 37305.0570432482. The cubic root of 1391667281 is about 1116.4650668162.

The spelling of 1391667281 in words is "one billion, three hundred ninety-one million, six hundred sixty-seven thousand, two hundred eighty-one".