165396661751 has 4 divisors (see below), whose sum is σ = 165398415672. Its totient is φ = 165394907832.

The previous prime is 165396661627. The next prime is 165396661753. The reversal of 165396661751 is 157166693561.

165396661751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165396661751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165396661753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 726956 + ... + 926961.

It is an arithmetic number, because the mean of its divisors is an integer number (41349603918).

Almost surely, 2^165396661751 is an apocalyptic number.

165396661751 is a deficient number, since it is larger than the sum of its proper divisors (1753921).

165396661751 is a wasteful number, since it uses less digits than its factorization.

165396661751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1753920.

The product of its digits is 6123600, while the sum is 56.

The spelling of 165396661751 in words is "one hundred sixty-five billion, three hundred ninety-six million, six hundred sixty-one thousand, seven hundred fifty-one".