18223920 has 320 divisors, whose sum is σ = 74995200. Its totient is φ = 4008960.

The previous prime is 18223913. The next prime is 18223927. The reversal of 18223920 is 2932281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18223913) and next prime (18223927).

It is a super-2 number, since 2×18223920² = 664222520332800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (18223927) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 308851 + ... + 308909.

It is an arithmetic number, because the mean of its divisors is an integer number (234360).

Almost surely, 2^18223920 is an apocalyptic number.

18223920 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 18223920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37497600).

18223920 is an abundant number, since it is smaller than the sum of its proper divisors (56771280).

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

18223920 is a wasteful number, since it uses less digits than its factorization.

18223920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18223920 is about 4268.9483482469. The cubic root of 18223920 is about 263.1563980827.

The spelling of 18223920 in words is "eighteen million, two hundred twenty-three thousand, nine hundred twenty".