291397 has 8 divisors (see below), whose sum is σ = 314712. Its totient is φ = 268800.

The previous prime is 291377. The next prime is 291419. The reversal of 291397 is 793192.

It can be written as a sum of positive squares in 4 ways, for example, as 30276 + 261121 = 174^2 + 511^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 291397 - 2¹¹ = 289349 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 (291337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 897 + ... + 1177.

It is an arithmetic number, because the mean of its divisors is an integer number (39339).

2²⁹¹³⁹⁷ is an apocalyptic number.

It is an amenable number.

291397 is a deficient number, since it is larger than the sum of its proper divisors (23315).

291397 is a wasteful number, since it uses less digits than its factorization.

291397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359.

The product of its digits is 3402, while the sum is 31.

The square root of 291397 is about 539.8120043126. The cubic root of 291397 is about 66.2971753705.

The spelling of 291397 in words is "two hundred ninety-one thousand, three hundred ninety-seven".