2531522221 has 2 divisors, whose sum is σ = 2531522222. Its totient is φ = 2531522220.

The previous prime is 2531522179. The next prime is 2531522233. The reversal of 2531522221 is 1222251352.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2461548996 + 69973225 = 49614^2 + 8365^2 .

It is a cyclic number.

It is not a de Polignac number, because 2531522221 - 2⁹ = 2531521709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2531522261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1265761110 + 1265761111.

It is an arithmetic number, because the mean of its divisors is an integer number (1265761111).

Almost surely, 2^2531522221 is an apocalyptic number.

It is an amenable number.

2531522221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2531522221 is an equidigital number, since it uses as much as digits as its factorization.

2531522221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 25.

The square root of 2531522221 is about 50314.2347750614. The cubic root of 2531522221 is about 1362.8892980220.

Adding to 2531522221 its reverse (1222251352), we get a palindrome (3753773573).

The spelling of 2531522221 in words is "two billion, five hundred thirty-one million, five hundred twenty-two thousand, two hundred twenty-one".