161505113917 has 12 divisors (see below), whose sum is σ = 188715789696. Its totient is φ = 137812169880.

The previous prime is 161505113909. The next prime is 161505113993. The reversal of 161505113917 is 719311505161.

It is a happy number.

It is not a de Polignac number, because 161505113917 - 2³ = 161505113909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161505113917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161505173917) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7379259 + ... + 7401112.

It is an arithmetic number, because the mean of its divisors is an integer number (15726315808).

Almost surely, 2^161505113917 is an apocalyptic number.

It is an amenable number.

161505113917 is a deficient number, since it is larger than the sum of its proper divisors (27210675779).

161505113917 is a wasteful number, since it uses less digits than its factorization.

161505113917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14780608 (or 14780601 counting only the distinct ones).

The product of its (nonzero) digits is 28350, while the sum is 40.

The spelling of 161505113917 in words is "one hundred sixty-one billion, five hundred five million, one hundred thirteen thousand, nine hundred seventeen".