18229920 has 96 divisors (see below), whose sum is σ = 58024512. Its totient is φ = 4810752.

The previous prime is 18229919. The next prime is 18229921. The reversal of 18229920 is 2992281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18229919) and next prime (18229921).

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (18229921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78124 + ... + 78356.

It is an arithmetic number, because the mean of its divisors is an integer number (604422).

Almost surely, 2^18229920 is an apocalyptic number.

18229920 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 18229920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29012256).

18229920 is an abundant number, since it is smaller than the sum of its proper divisors (39794592).

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

18229920 is a wasteful number, since it uses less digits than its factorization.

18229920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 18229920 is about 4269.6510396050. The cubic root of 18229920 is about 263.1852752423.

The spelling of 18229920 in words is "eighteen million, two hundred twenty-nine thousand, nine hundred twenty".