391117 has 2 divisors, whose sum is σ = 391118. Its totient is φ = 391116.

The previous prime is 391103. The next prime is 391133. The reversal of 391117 is 711193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 385641 + 5476 = 621^2 + 74^2 .

It is a cyclic number.

It is not a de Polignac number, because 391117 - 2⁷ = 390989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195558 + 195559.

It is an arithmetic number, because the mean of its divisors is an integer number (195559).

2³⁹¹¹¹⁷ is an apocalyptic number.

It is an amenable number.

391117 is a deficient number, since it is larger than the sum of its proper divisors (1).

391117 is an equidigital number, since it uses as much as digits as its factorization.

391117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189, while the sum is 22.

The square root of 391117 is about 625.3934761412. The cubic root of 391117 is about 73.1311210694.

It can be divided in two parts, 39 and 1117, that added together give a square (1156 = 34²).

The spelling of 391117 in words is "three hundred ninety-one thousand, one hundred seventeen".