2518865821 has 2 divisors, whose sum is σ = 2518865822. Its totient is φ = 2518865820.

The previous prime is 2518865779. The next prime is 2518865857. The reversal of 2518865821 is 1285688152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2096357796 + 422508025 = 45786^2 + 20555^2 .

It is a cyclic number.

It is not a de Polignac number, because 2518865821 - 2¹³ = 2518857629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2518865221) 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 as a sum of consecutive naturals, namely, 1259432910 + 1259432911.

It is an arithmetic number, because the mean of its divisors is an integer number (1259432911).

Almost surely, 2^2518865821 is an apocalyptic number.

It is an amenable number.

2518865821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2518865821 is an equidigital number, since it uses as much as digits as its factorization.

2518865821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 307200, while the sum is 46.

The square root of 2518865821 is about 50188.3036274389. The cubic root of 2518865821 is about 1360.6142375710.

The spelling of 2518865821 in words is "two billion, five hundred eighteen million, eight hundred sixty-five thousand, eight hundred twenty-one".