18778380 has 48 divisors (see below), whose sum is σ = 53706240. Its totient is φ = 4900288.

The previous prime is 18778363. The next prime is 18778381. The reversal of 18778380 is 8387781.

It is a super-3 number, since 3×18778380³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (18778381) 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, 510 + ... + 6149.

It is an arithmetic number, because the mean of its divisors is an integer number (1118880).

Almost surely, 2^18778380 is an apocalyptic number.

18778380 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 18778380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26853120).

18778380 is an abundant number, since it is smaller than the sum of its proper divisors (34927860).

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

18778380 is a wasteful number, since it uses less digits than its factorization.

18778380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6718 (or 6716 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 42.

The square root of 18778380 is about 4333.4028199557. The cubic root of 18778380 is about 265.7986113940.

The spelling of 18778380 in words is "eighteen million, seven hundred seventy-eight thousand, three hundred eighty".