161861718 has 32 divisors (see below), whose sum is σ = 345666816. Its totient is φ = 50406048.

The previous prime is 161861699. The next prime is 161861737. The reversal of 161861718 is 817168161.

It is an interprime number because it is at equal distance from previous prime (161861699) and next prime (161861737).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7705 + ... + 19572.

It is an arithmetic number, because the mean of its divisors is an integer number (10802088).

Almost surely, 2^161861718 is an apocalyptic number.

161861718 is an abundant number, since it is smaller than the sum of its proper divisors (183805098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161861718 is a wasteful number, since it uses less digits than its factorization.

161861718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27348.

The product of its digits is 16128, while the sum is 39.

The square root of 161861718 is about 12722.4886716397. The cubic root of 161861718 is about 544.9810256279.

It can be divided in two parts, 1618 and 61718, that added together give a palindrome (63336).

The spelling of 161861718 in words is "one hundred sixty-one million, eight hundred sixty-one thousand, seven hundred eighteen".