161789718619 has 4 divisors (see below), whose sum is σ = 161790854080. Its totient is φ = 161788583160.

The previous prime is 161789718613. The next prime is 161789718637. The reversal of 161789718619 is 916817987161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 161789718619 - 2⁹ = 161789718107 is a prime.

It is a super-2 number, since 2×161789718619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161789718613) 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, 317124 + ... + 651265.

It is an arithmetic number, because the mean of its divisors is an integer number (40447713520).

Almost surely, 2^161789718619 is an apocalyptic number.

161789718619 is a deficient number, since it is larger than the sum of its proper divisors (1135461).

161789718619 is an equidigital number, since it uses as much as digits as its factorization.

161789718619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135460.

The product of its digits is 9144576, while the sum is 64.

The spelling of 161789718619 in words is "one hundred sixty-one billion, seven hundred eighty-nine million, seven hundred eighteen thousand, six hundred nineteen".