2518865221 has 2 divisors, whose sum is σ = 2518865222. Its totient is φ = 2518865220.

The previous prime is 2518865213. The next prime is 2518865233. The reversal of 2518865221 is 1225688152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1847796196 + 671069025 = 42986^2 + 25905^2 .

It is a cyclic number.

It is not a de Polignac number, because 2518865221 - 2³ = 2518865213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2518865281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1259432610 + 1259432611.

It is an arithmetic number, because the mean of its divisors is an integer number (1259432611).

Almost surely, 2^2518865221 is an apocalyptic number.

It is an amenable number.

2518865221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2518865221 is an equidigital number, since it uses as much as digits as its factorization.

2518865221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76800, while the sum is 40.

The square root of 2518865221 is about 50188.2976499502. The cubic root of 2518865221 is about 1360.6141295371.

It can be divided in two parts, 25188 and 65221, that added together give a palindrome (90409).

The spelling of 2518865221 in words is "two billion, five hundred eighteen million, eight hundred sixty-five thousand, two hundred twenty-one".