18851920 has 40 divisors (see below), whose sum is σ = 44461440. Its totient is φ = 7432320.

The previous prime is 18851909. The next prime is 18851939. The reversal of 18851920 is 2915881.

It is a tau number, because it is divible by the number of its divisors (40).

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 7 ways as a sum of consecutive naturals, for example, 4021 + ... + 7339.

It is an arithmetic number, because the mean of its divisors is an integer number (1111536).

Almost surely, 2^18851920 is an apocalyptic number.

18851920 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 18851920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22230720).

18851920 is an abundant number, since it is smaller than the sum of its proper divisors (25609520).

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

18851920 is a wasteful number, since it uses less digits than its factorization.

18851920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3403 (or 3397 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 18851920 is about 4341.8797772393. The cubic root of 18851920 is about 266.1451334544.

The spelling of 18851920 in words is "eighteen million, eight hundred fifty-one thousand, nine hundred twenty".