2165321240166 has 32 divisors (see below), whose sum is σ = 4949511459840. Its totient is φ = 618637490496.

The previous prime is 2165321240161. The next prime is 2165321240189. The reversal of 2165321240166 is 6610421235612.

It is a super-2 number, since 2×2165321240166² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165321240161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37726 + ... + 2081361.

It is an arithmetic number, because the mean of its divisors is an integer number (154672233120).

Almost surely, 2^{2165321240166} is an apocalyptic number.

2165321240166 is an abundant number, since it is smaller than the sum of its proper divisors (2784190219674).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2165321240166 is a wasteful number, since it uses less digits than its factorization.

2165321240166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143428.

The product of its (nonzero) digits is 103680, while the sum is 39.

Adding to 2165321240166 its reverse (6610421235612), we get a palindrome (8775742475778).

The spelling of 2165321240166 in words is "two trillion, one hundred sixty-five billion, three hundred twenty-one million, two hundred forty thousand, one hundred sixty-six".