1391917 has 2 divisors, whose sum is σ = 1391918. Its totient is φ = 1391916.

The previous prime is 1391899. The next prime is 1391927. The reversal of 1391917 is 7191931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1179396 + 212521 = 1086^2 + 461^2 .

It is an emirp because it is prime and its reverse (7191931) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1391917 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1391927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695958 + 695959.

It is an arithmetic number, because the mean of its divisors is an integer number (695959).

2^1391917 is an apocalyptic number.

It is an amenable number.

1391917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391917 is an equidigital number, since it uses as much as digits as its factorization.

1391917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1701, while the sum is 31.

The square root of 1391917 is about 1179.7953212316. The cubic root of 1391917 is about 111.6531841844.

The spelling of 1391917 in words is "one million, three hundred ninety-one thousand, nine hundred seventeen".