518023021 has 4 divisors (see below), whose sum is σ = 530070112. Its totient is φ = 505975932.

The previous prime is 518022983. The next prime is 518023039. The reversal of 518023021 is 120320815.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 518023021 - 2⁹ = 518022509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 518022983 and 518023001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (518023061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6023481 + ... + 6023566.

It is an arithmetic number, because the mean of its divisors is an integer number (132517528).

Almost surely, 2^518023021 is an apocalyptic number.

It is an amenable number.

518023021 is a deficient number, since it is larger than the sum of its proper divisors (12047091).

518023021 is a wasteful number, since it uses less digits than its factorization.

518023021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12047090.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 518023021 is about 22760.1190901981. The cubic root of 518023021 is about 803.1247689866.

Adding to 518023021 its reverse (120320815), we get a palindrome (638343836).

The spelling of 518023021 in words is "five hundred eighteen million, twenty-three thousand, twenty-one".