2161388865773 has 2 divisors, whose sum is σ = 2161388865774. Its totient is φ = 2161388865772.

The previous prime is 2161388865739. The next prime is 2161388865793. The reversal of 2161388865773 is 3775688831612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1464494486569 + 696894379204 = 1210163^2 + 834802^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161388865773 - 2¹² = 2161388861677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161388865793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080694432886 + 1080694432887.

It is an arithmetic number, because the mean of its divisors is an integer number (1080694432887).

Almost surely, 2^{2161388865773} is an apocalyptic number.

It is an amenable number.

2161388865773 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161388865773 is an equidigital number, since it uses as much as digits as its factorization.

2161388865773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81285120, while the sum is 65.

The spelling of 2161388865773 in words is "two trillion, one hundred sixty-one billion, three hundred eighty-eight million, eight hundred sixty-five thousand, seven hundred seventy-three".