518921 has 8 divisors (see below), whose sum is σ = 564480. Its totient is φ = 474192.

The previous prime is 518911. The next prime is 518933. The reversal of 518921 is 129815.

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 a de Polignac number, because none of the positive numbers 2^k-518921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (518911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2216 + ... + 2438.

It is an arithmetic number, because the mean of its divisors is an integer number (70560).

2⁵¹⁸⁹²¹ is an apocalyptic number.

It is an amenable number.

518921 is a deficient number, since it is larger than the sum of its proper divisors (45559).

518921 is a wasteful number, since it uses less digits than its factorization.

518921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415.

The product of its digits is 720, while the sum is 26.

The square root of 518921 is about 720.3617146962. The cubic root of 518921 is about 80.3588566172.

The spelling of 518921 in words is "five hundred eighteen thousand, nine hundred twenty-one".