161813418 has 32 divisors (see below), whose sum is σ = 363678336. Its totient is φ = 47623488.

The previous prime is 161813389. The next prime is 161813423. The reversal of 161813418 is 814318161.

It is a happy 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, 43305 + ... + 46892.

It is an arithmetic number, because the mean of its divisors is an integer number (11364948).

Almost surely, 2^161813418 is an apocalyptic number.

161813418 is an abundant number, since it is smaller than the sum of its proper divisors (201864918).

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

161813418 is a wasteful number, since it uses less digits than its factorization.

161813418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90238.

The product of its digits is 4608, while the sum is 33.

The square root of 161813418 is about 12720.5903164908. The cubic root of 161813418 is about 544.9268122690.

The spelling of 161813418 in words is "one hundred sixty-one million, eight hundred thirteen thousand, four hundred eighteen".