165688637 has 2 divisors, whose sum is σ = 165688638. Its totient is φ = 165688636.

The previous prime is 165688631. The next prime is 165688639. The reversal of 165688637 is 736886561.

It is a happy number.

165688637 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162664516 + 3024121 = 12754^2 + 1739^2 .

It is a cyclic number.

It is not a de Polignac number, because 165688637 - 2¹⁴ = 165672253 is a prime.

Together with 165688639, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165688631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82844318 + 82844319.

It is an arithmetic number, because the mean of its divisors is an integer number (82844319).

Almost surely, 2^165688637 is an apocalyptic number.

It is an amenable number.

165688637 is a deficient number, since it is larger than the sum of its proper divisors (1).

165688637 is an equidigital number, since it uses as much as digits as its factorization.

165688637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 50.

The square root of 165688637 is about 12872.0098275289. The cubic root of 165688637 is about 549.2426347006.

The spelling of 165688637 in words is "one hundred sixty-five million, six hundred eighty-eight thousand, six hundred thirty-seven".