18943380 has 144 divisors (see below), whose sum is σ = 62899200. Its totient is φ = 4596480.

The previous prime is 18943363. The next prime is 18943381. The reversal of 18943380 is 8334981.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18943381) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 99085 + ... + 99275.

It is an arithmetic number, because the mean of its divisors is an integer number (436800).

Almost surely, 2^18943380 is an apocalyptic number.

18943380 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 18943380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31449600).

18943380 is an abundant number, since it is smaller than the sum of its proper divisors (43955820).

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

18943380 is a wasteful number, since it uses less digits than its factorization.

18943380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 18943380 is about 4352.3993382961. The cubic root of 18943380 is about 266.5748399108.

The spelling of 18943380 in words is "eighteen million, nine hundred forty-three thousand, three hundred eighty".