19505580161 has 4 divisors (see below), whose sum is σ = 19544670000. Its totient is φ = 19466490324.

The previous prime is 19505580131. The next prime is 19505580167. The reversal of 19505580161 is 16108550591.

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 not a de Polignac number, because 19505580161 - 2²² = 19501385857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19505580167) 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, 19544171 + ... + 19545168.

It is an arithmetic number, because the mean of its divisors is an integer number (4886167500).

Almost surely, 2^19505580161 is an apocalyptic number.

It is an amenable number.

19505580161 is a deficient number, since it is larger than the sum of its proper divisors (39089839).

19505580161 is an equidigital number, since it uses as much as digits as its factorization.

19505580161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39089838.

The product of its (nonzero) digits is 54000, while the sum is 41.

The spelling of 19505580161 in words is "nineteen billion, five hundred five million, five hundred eighty thousand, one hundred sixty-one".