18949840 has 160 divisors (see below), whose sum is σ = 57496320. Its totient is φ = 5640192.

The previous prime is 18949817. The next prime is 18949841. The reversal of 18949840 is 4894981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18949841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138252 + ... + 138388.

It is an arithmetic number, because the mean of its divisors is an integer number (359352).

Almost surely, 2^18949840 is an apocalyptic number.

18949840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18949840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28748160).

18949840 is an abundant number, since it is smaller than the sum of its proper divisors (38546480).

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

18949840 is a wasteful number, since it uses less digits than its factorization.

18949840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 18949840 is about 4353.1413944415. The cubic root of 18949840 is about 266.6051385825.

The spelling of 18949840 in words is "eighteen million, nine hundred forty-nine thousand, eight hundred forty".