2116645301821 has 2 divisors, whose sum is σ = 2116645301822. Its totient is φ = 2116645301820.

The previous prime is 2116645301773. The next prime is 2116645301843. The reversal of 2116645301821 is 1281035466112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1983576476025 + 133068825796 = 1408395^2 + 364786^2 .

It is a cyclic number.

It is not a de Polignac number, because 2116645301821 - 2²³ = 2116636913213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2116645301891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1058322650910 + 1058322650911.

It is an arithmetic number, because the mean of its divisors is an integer number (1058322650911).

Almost surely, 2^{2116645301821} is an apocalyptic number.

It is an amenable number.

2116645301821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2116645301821 is an equidigital number, since it uses as much as digits as its factorization.

2116645301821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 2116645301821 in words is "two trillion, one hundred sixteen billion, six hundred forty-five million, three hundred one thousand, eight hundred twenty-one".