2215556521 has 2 divisors, whose sum is σ = 2215556522. Its totient is φ = 2215556520.

The previous prime is 2215556461. The next prime is 2215556527. The reversal of 2215556521 is 1256555122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1774094400 + 441462121 = 42120^2 + 21011^2 .

It is a cyclic number.

It is not a de Polignac number, because 2215556521 - 2⁷ = 2215556393 is a prime.

It is not a weakly prime, because it can be changed into another prime (2215556527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1107778260 + 1107778261.

It is an arithmetic number, because the mean of its divisors is an integer number (1107778261).

Almost surely, 2^2215556521 is an apocalyptic number.

It is an amenable number.

2215556521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2215556521 is an equidigital number, since it uses as much as digits as its factorization.

2215556521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30000, while the sum is 34.

The square root of 2215556521 is about 47069.6985437553. The cubic root of 2215556521 is about 1303.6498067323.

The spelling of 2215556521 in words is "two billion, two hundred fifteen million, five hundred fifty-six thousand, five hundred twenty-one".