2116545220665 has 12 divisors (see below), whose sum is σ = 3668678382564. Its totient is φ = 1128824117664.

The previous prime is 2116545220639. The next prime is 2116545220687. The reversal of 2116545220665 is 5660225456112.

2116545220665 is a `hidden beast` number, since 2 + 1 + 1 + 65 + 4 + 522 + 0 + 6 + 65 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1555587661824 + 560957558841 = 1247232^2 + 748971^2 .

It is not a de Polignac number, because 2116545220665 - 2⁸ = 2116545220409 is a prime.

It is a super-2 number, since 2×2116545220665² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 47034338237 = 2116545220665 / (2 + 1 + 1 + 6 + 5 + 4 + 5 + 2 + 2 + 0 + 6 + 6 + 5).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2116545220665.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23517169074 + ... + 23517169163.

It is an arithmetic number, because the mean of its divisors is an integer number (305723198547).

Almost surely, 2^{2116545220665} is an apocalyptic number.

It is an amenable number.

2116545220665 is a deficient number, since it is larger than the sum of its proper divisors (1552133161899).

2116545220665 is a wasteful number, since it uses less digits than its factorization.

2116545220665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47034338248 (or 47034338245 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 45.

The spelling of 2116545220665 in words is "two trillion, one hundred sixteen billion, five hundred forty-five million, two hundred twenty thousand, six hundred sixty-five".