161953243555 has 4 divisors (see below), whose sum is σ = 194343892272. Its totient is φ = 129562594840.

The previous prime is 161953243523. The next prime is 161953243577. The reversal of 161953243555 is 555342359161.

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

It is not a de Polignac number, because 161953243555 - 2⁵ = 161953243523 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161953243499 and 161953243508.

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, 16195324351 + ... + 16195324360.

It is an arithmetic number, because the mean of its divisors is an integer number (48585973068).

Almost surely, 2^161953243555 is an apocalyptic number.

161953243555 is a deficient number, since it is larger than the sum of its proper divisors (32390648717).

161953243555 is an equidigital number, since it uses as much as digits as its factorization.

161953243555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32390648716.

The product of its digits is 2430000, while the sum is 49.

The spelling of 161953243555 in words is "one hundred sixty-one billion, nine hundred fifty-three million, two hundred forty-three thousand, five hundred fifty-five".