2165204137 has 4 divisors (see below), whose sum is σ = 2218014036. Its totient is φ = 2112394240.

The previous prime is 2165204123. The next prime is 2165204159. The reversal of 2165204137 is 7314025612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 254115481 + 1911088656 = 15941^2 + 43716^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165204137 - 2¹⁵ = 2165171369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2165204099 and 2165204108.

It is not an unprimeable number, because it can be changed into a prime (2165204737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26404888 + ... + 26404969.

It is an arithmetic number, because the mean of its divisors is an integer number (554503509).

Almost surely, 2^2165204137 is an apocalyptic number.

It is an amenable number.

2165204137 is a deficient number, since it is larger than the sum of its proper divisors (52809899).

2165204137 is an equidigital number, since it uses as much as digits as its factorization.

2165204137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52809898.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 2165204137 is about 46531.7540718164. The cubic root of 2165204137 is about 1293.6981270652.

Adding to 2165204137 its reverse (7314025612), we get a palindrome (9479229749).

The spelling of 2165204137 in words is "two billion, one hundred sixty-five million, two hundred four thousand, one hundred thirty-seven".