18151920 has 120 divisors (see below), whose sum is σ = 64589616. Its totient is φ = 4552704.

The previous prime is 18151877. The next prime is 18151921. The reversal of 18151920 is 2915181.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18151921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11499 + ... + 12981.

Almost surely, 2^18151920 is an apocalyptic number.

18151920 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 18151920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32294808).

18151920 is an abundant number, since it is smaller than the sum of its proper divisors (46437696).

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

18151920 is a wasteful number, since it uses less digits than its factorization.

18151920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519 (or 1510 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 18151920 is about 4260.5070120820. The cubic root of 18151920 is about 262.8093767287.

The spelling of 18151920 in words is "eighteen million, one hundred fifty-one thousand, nine hundred twenty".