2165140066 has 4 divisors (see below), whose sum is σ = 3247710102. Its totient is φ = 1082570032.

The previous prime is 2165140049. The next prime is 2165140067. The reversal of 2165140066 is 6600415612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2142301225 + 22838841 = 46285^2 + 4779^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2165140067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 541285015 + ... + 541285018.

Almost surely, 2^2165140066 is an apocalyptic number.

2165140066 is a deficient number, since it is larger than the sum of its proper divisors (1082570036).

2165140066 is a wasteful number, since it uses less digits than its factorization.

2165140066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082570035.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 2165140066 is about 46531.0656013808. The cubic root of 2165140066 is about 1293.6853662437.

Adding to 2165140066 its reverse (6600415612), we get a palindrome (8765555678).

The spelling of 2165140066 in words is "two billion, one hundred sixty-five million, one hundred forty thousand, sixty-six".