18855856 has 40 divisors (see below), whose sum is σ = 38997504. Its totient is φ = 8801280.

The previous prime is 18855853. The next prime is 18855899. The reversal of 18855856 is 65855881.

18855856 = T₃₅₄₄ + T₃₅₄₅ + T₃₅₄₆.

It is not an unprimeable number, because it can be changed into a prime (18855853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49041 + ... + 49423.

Almost surely, 2^18855856 is an apocalyptic number.

18855856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

18855856 is the 3546-th centered triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18855856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19498752).

18855856 is an abundant number, since it is smaller than the sum of its proper divisors (20141648).

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

18855856 is a wasteful number, since it uses less digits than its factorization.

18855856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 583 counting only the distinct ones).

The product of its digits is 384000, while the sum is 46.

The square root of 18855856 is about 4342.3330134848. Note that the first 3 decimals coincide. The cubic root of 18855856 is about 266.1636545449.

The spelling of 18855856 in words is "eighteen million, eight hundred fifty-five thousand, eight hundred fifty-six".