165551388193 has 4 divisors (see below), whose sum is σ = 167158683328. Its totient is φ = 163944093060.

The previous prime is 165551388179. The next prime is 165551388199. The reversal of 165551388193 is 391883155561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 391883155561 = 196681 ⋅1992481.

It is a cyclic number.

It is not a de Polignac number, because 165551388193 - 2⁵ = 165551388161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165551388199) 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, 803647413 + ... + 803647618.

It is an arithmetic number, because the mean of its divisors is an integer number (41789670832).

Almost surely, 2^165551388193 is an apocalyptic number.

It is an amenable number.

165551388193 is a deficient number, since it is larger than the sum of its proper divisors (1607295135).

165551388193 is a wasteful number, since it uses less digits than its factorization.

165551388193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1607295134.

The product of its digits is 3888000, while the sum is 55.

The spelling of 165551388193 in words is "one hundred sixty-five billion, five hundred fifty-one million, three hundred eighty-eight thousand, one hundred ninety-three".