2116345661 has 2 divisors, whose sum is σ = 2116345662. Its totient is φ = 2116345660.

The previous prime is 2116345643. The next prime is 2116345681. The reversal of 2116345661 is 1665436112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1359765625 + 756580036 = 36875^2 + 27506^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2116345661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2116345631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1058172830 + 1058172831.

It is an arithmetic number, because the mean of its divisors is an integer number (1058172831).

Almost surely, 2^2116345661 is an apocalyptic number.

It is an amenable number.

2116345661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2116345661 is an equidigital number, since it uses as much as digits as its factorization.

2116345661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The square root of 2116345661 is about 46003.7570313556. The cubic root of 2116345661 is about 1283.8931074743.

The spelling of 2116345661 in words is "two billion, one hundred sixteen million, three hundred forty-five thousand, six hundred sixty-one".