1393681 has 2 divisors, whose sum is σ = 1393682. Its totient is φ = 1393680.

The previous prime is 1393663. The next prime is 1393687. The reversal of 1393681 is 1863931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1245456 + 148225 = 1116^2 + 385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1393681 - 2⁵ = 1393649 is a prime.

It is a super-2 number, since 2×1393681² = 3884693459522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1393687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 696840 + 696841.

It is an arithmetic number, because the mean of its divisors is an integer number (696841).

2^1393681 is an apocalyptic number.

It is an amenable number.

1393681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1393681 is an equidigital number, since it uses as much as digits as its factorization.

1393681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 1393681 is about 1180.5426718251. The cubic root of 1393681 is about 111.7003309308.

The spelling of 1393681 in words is "one million, three hundred ninety-three thousand, six hundred eighty-one".