18161910 has 144 divisors (see below), whose sum is σ = 54918864. Its totient is φ = 4136832.

The previous prime is 18161903. The next prime is 18161947. The reversal of 18161910 is 1916181.

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 (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 422349 + ... + 422391.

It is an arithmetic number, because the mean of its divisors is an integer number (381381).

Almost surely, 2^18161910 is an apocalyptic number.

18161910 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18161910, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27459432).

18161910 is an abundant number, since it is smaller than the sum of its proper divisors (36756954).

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

18161910 is a wasteful number, since it uses less digits than its factorization.

18161910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 27.

The square root of 18161910 is about 4261.6792464943. The cubic root of 18161910 is about 262.8575807052.

The spelling of 18161910 in words is "eighteen million, one hundred sixty-one thousand, nine hundred ten".