291387 has 16 divisors (see below), whose sum is σ = 419328. Its totient is φ = 179520.

The previous prime is 291377. The next prime is 291419. The reversal of 291387 is 783192.

It is a happy number.

It is not a de Polignac number, because 291387 - 2⁴ = 291371 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 2778 + ... + 2880.

It is an arithmetic number, because the mean of its divisors is an integer number (26208).

2²⁹¹³⁸⁷ is an apocalyptic number.

291387 is a deficient number, since it is larger than the sum of its proper divisors (127941).

291387 is a wasteful number, since it uses less digits than its factorization.

291387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170.

The product of its digits is 3024, while the sum is 30.

The square root of 291387 is about 539.8027417492. The cubic root of 291387 is about 66.2964169786.

The spelling of 291387 in words is "two hundred ninety-one thousand, three hundred eighty-seven".