18161646 has 16 divisors (see below), whose sum is σ = 37096704. Its totient is φ = 5924984.

The previous prime is 18161641. The next prime is 18161657. The reversal of 18161646 is 64616181.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18161641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31920 + ... + 32483.

It is an arithmetic number, because the mean of its divisors is an integer number (2318544).

Almost surely, 2^18161646 is an apocalyptic number.

18161646 is an abundant number, since it is smaller than the sum of its proper divisors (18935058).

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

18161646 is a wasteful number, since it uses less digits than its factorization.

18161646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64455.

The product of its digits is 6912, while the sum is 33.

The square root of 18161646 is about 4261.6482726757. The cubic root of 18161646 is about 262.8563070738.

The spelling of 18161646 in words is "eighteen million, one hundred sixty-one thousand, six hundred forty-six".