165190681 has 8 divisors (see below), whose sum is σ = 173794824. Its totient is φ = 156804480.

The previous prime is 165190657. The next prime is 165190703. The reversal of 165190681 is 186091561.

It can be written as a sum of positive squares in 4 ways, for example, as 15960025 + 149230656 = 3995^2 + 12216^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165190681 - 2¹⁵ = 165157913 is a prime.

It is a super-2 number, since 2×165190681² = 54575922178487522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165190681.

It is not an unprimeable number, because it can be changed into a prime (165190621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52930 + ... + 55963.

It is an arithmetic number, because the mean of its divisors is an integer number (21724353).

Almost surely, 2^165190681 is an apocalyptic number.

It is an amenable number.

165190681 is a deficient number, since it is larger than the sum of its proper divisors (8604143).

165190681 is a wasteful number, since it uses less digits than its factorization.

165190681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108971.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 165190681 is about 12852.6526833958. The cubic root of 165190681 is about 548.6918564112.

The spelling of 165190681 in words is "one hundred sixty-five million, one hundred ninety thousand, six hundred eighty-one".