161757727813 has 4 divisors (see below), whose sum is σ = 176462975808. Its totient is φ = 147052479820.

The previous prime is 161757727699. The next prime is 161757727819. The reversal of 161757727813 is 318727757161.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161757727813 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 (161757727819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7352623981 + ... + 7352624002.

It is an arithmetic number, because the mean of its divisors is an integer number (44115743952).

Almost surely, 2^161757727813 is an apocalyptic number.

It is an amenable number.

161757727813 is a deficient number, since it is larger than the sum of its proper divisors (14705247995).

161757727813 is a wasteful number, since it uses less digits than its factorization.

161757727813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14705247994.

The product of its digits is 3457440, while the sum is 55.

The spelling of 161757727813 in words is "one hundred sixty-one billion, seven hundred fifty-seven million, seven hundred twenty-seven thousand, eight hundred thirteen".