16181998 has 16 divisors (see below), whose sum is σ = 27828864. Its totient is φ = 6913080.

The previous prime is 16181981. The next prime is 16181999. The reversal of 16181998 is 89918161.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16181999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3193 + ... + 6523.

It is an arithmetic number, because the mean of its divisors is an integer number (1739304).

Almost surely, 2^16181998 is an apocalyptic number.

16181998 is a deficient number, since it is larger than the sum of its proper divisors (11646866).

16181998 is a wasteful number, since it uses less digits than its factorization.

16181998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3687.

The product of its digits is 31104, while the sum is 43.

The square root of 16181998 is about 4022.6854214567. The cubic root of 16181998 is about 252.9360396989.

The spelling of 16181998 in words is "sixteen million, one hundred eighty-one thousand, nine hundred ninety-eight".