2215311521 has 2 divisors, whose sum is σ = 2215311522. Its totient is φ = 2215311520.

The previous prime is 2215311481. The next prime is 2215311523. The reversal of 2215311521 is 1251135122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2149620496 + 65691025 = 46364^2 + 8105^2 .

It is a cyclic number.

It is not a de Polignac number, because 2215311521 - 2¹⁰ = 2215310497 is a prime.

Together with 2215311523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2215311523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1107655760 + 1107655761.

It is an arithmetic number, because the mean of its divisors is an integer number (1107655761).

Almost surely, 2^2215311521 is an apocalyptic number.

It is an amenable number.

2215311521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2215311521 is an equidigital number, since it uses as much as digits as its factorization.

2215311521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 600, while the sum is 23.

The square root of 2215311521 is about 47067.0959482312. The cubic root of 2215311521 is about 1303.6017516916.

Adding to 2215311521 its reverse (1251135122), we get a palindrome (3466446643).

The spelling of 2215311521 in words is "two billion, two hundred fifteen million, three hundred eleven thousand, five hundred twenty-one".