978591 has 8 divisors (see below), whose sum is σ = 1314864. Its totient is φ = 647360.

The previous prime is 978569. The next prime is 978599. The reversal of 978591 is 195879.

It is a happy number.

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 978591 - 2⁷ = 978463 is a prime.

978591 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978599) 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, 780 + ... + 1601.

It is an arithmetic number, because the mean of its divisors is an integer number (164358).

2⁹⁷⁸⁵⁹¹ is an apocalyptic number.

978591 is a deficient number, since it is larger than the sum of its proper divisors (336273).

978591 is a wasteful number, since it uses less digits than its factorization.

978591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521.

The product of its digits is 22680, while the sum is 39.

The square root of 978591 is about 989.2375852140. The cubic root of 978591 is about 99.2812124907.

The spelling of 978591 in words is "nine hundred seventy-eight thousand, five hundred ninety-one".