391157 has 4 divisors (see below), whose sum is σ = 421260. Its totient is φ = 361056.

The previous prime is 391151. The next prime is 391159. The reversal of 391157 is 751193.

391157 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 119716 + 271441 = 346^2 + 521^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-391157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15032 + ... + 15057.

It is an arithmetic number, because the mean of its divisors is an integer number (105315).

2³⁹¹¹⁵⁷ is an apocalyptic number.

It is an amenable number.

391157 is a deficient number, since it is larger than the sum of its proper divisors (30103).

391157 is a wasteful number, since it uses less digits than its factorization.

391157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30102.

The product of its digits is 945, while the sum is 26.

The square root of 391157 is about 625.4254551903. The cubic root of 391157 is about 73.1336140533.

The spelling of 391157 in words is "three hundred ninety-one thousand, one hundred fifty-seven".