2216245781 has 2 divisors, whose sum is σ = 2216245782. Its totient is φ = 2216245780.

The previous prime is 2216245777. The next prime is 2216245807. The reversal of 2216245781 is 1875426122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1777971556 + 438274225 = 42166^2 + 20935^2 .

It is a cyclic number.

It is not a de Polignac number, because 2216245781 - 2² = 2216245777 is a prime.

It is a super-2 number, since 2×2216245781² = 9823490723600599922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2216245081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1108122890 + 1108122891.

It is an arithmetic number, because the mean of its divisors is an integer number (1108122891).

Almost surely, 2^2216245781 is an apocalyptic number.

It is an amenable number.

2216245781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2216245781 is an equidigital number, since it uses as much as digits as its factorization.

2216245781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 38.

The square root of 2216245781 is about 47077.0196698984. The cubic root of 2216245781 is about 1303.7849812725.

The spelling of 2216245781 in words is "two billion, two hundred sixteen million, two hundred forty-five thousand, seven hundred eighty-one".