518254021 has 2 divisors, whose sum is σ = 518254022. Its totient is φ = 518254020.

The previous prime is 518254019. The next prime is 518254057. The reversal of 518254021 is 120452815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 491109921 + 27144100 = 22161^2 + 5210^2 .

It is a cyclic number.

It is not a de Polignac number, because 518254021 - 2¹ = 518254019 is a prime.

Together with 518254019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518254081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259127010 + 259127011.

It is an arithmetic number, because the mean of its divisors is an integer number (259127011).

Almost surely, 2^518254021 is an apocalyptic number.

It is an amenable number.

518254021 is a deficient number, since it is larger than the sum of its proper divisors (1).

518254021 is an equidigital number, since it uses as much as digits as its factorization.

518254021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 518254021 is about 22765.1931904827. The cubic root of 518254021 is about 803.2441293526.

The spelling of 518254021 in words is "five hundred eighteen million, two hundred fifty-four thousand, twenty-one".