161892018 has 18 divisors (see below), whose sum is σ = 350883039. Its totient is φ = 53946012.

The previous prime is 161891993. The next prime is 161892019. The reversal of 161892018 is 810298161.

161892018 is a `hidden beast` number, since 1 + 618 + 9 + 20 + 18 = 666.

It can be written as a sum of positive squares in only one way, i.e., 80946009 + 80946009 = 8997^2 + 8997^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=8997.

It is a super-2 number, since 2×161892018² = 52418050984224648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161892019) by changing a digit.

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 8 ways as a sum of consecutive naturals, for example, 52483 + ... + 55481.

Almost surely, 2^161892018 is an apocalyptic number.

161892018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161892018 is an abundant number, since it is smaller than the sum of its proper divisors (188991021).

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

161892018 is an frugal number, since it uses more digits than its factorization.

161892018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6006 (or 3004 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 161892018 is about 12723.6794206707. The cubic root of 161892018 is about 545.0150297457.

It can be divided in two parts, 1618 and 92018, that added together give a square (93636 = 306²).

The spelling of 161892018 in words is "one hundred sixty-one million, eight hundred ninety-two thousand, eighteen".