165651851 has 4 divisors (see below), whose sum is σ = 165760752. Its totient is φ = 165542952.

The previous prime is 165651841. The next prime is 165651853. The reversal of 165651851 is 158156561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 158156561 = 4817 ⋅32833.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165651851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165651853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52136 + ... + 55221.

It is an arithmetic number, because the mean of its divisors is an integer number (41440188).

Almost surely, 2^165651851 is an apocalyptic number.

165651851 is a deficient number, since it is larger than the sum of its proper divisors (108901).

165651851 is a wasteful number, since it uses less digits than its factorization.

165651851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108900.

The product of its digits is 36000, while the sum is 38.

The square root of 165651851 is about 12870.5808338241. The cubic root of 165651851 is about 549.2019842867.

The spelling of 165651851 in words is "one hundred sixty-five million, six hundred fifty-one thousand, eight hundred fifty-one".