161311811735 has 4 divisors (see below), whose sum is σ = 193574174088. Its totient is φ = 129049449384.

The previous prime is 161311811723. The next prime is 161311811807. The reversal of 161311811735 is 537118113161.

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

It is a cyclic number.

It is not a de Polignac number, because 161311811735 - 2³⁰ = 160238069911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16131181169 + ... + 16131181178.

It is an arithmetic number, because the mean of its divisors is an integer number (48393543522).

Almost surely, 2^161311811735 is an apocalyptic number.

161311811735 is a deficient number, since it is larger than the sum of its proper divisors (32262362353).

161311811735 is an equidigital number, since it uses as much as digits as its factorization.

161311811735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32262362352.

The product of its digits is 15120, while the sum is 38.

Adding to 161311811735 its reverse (537118113161), we get a palindrome (698429924896).

The spelling of 161311811735 in words is "one hundred sixty-one billion, three hundred eleven million, eight hundred eleven thousand, seven hundred thirty-five".