18844540 has 72 divisors (see below), whose sum is σ = 46922400. Its totient is φ = 6314880.

The previous prime is 18844537. The next prime is 18844549. The reversal of 18844540 is 4544881.

18844540 = T₂₉₉ + T₃₀₀ + ... + T₅₁₈.

It is a junction number, because it is equal to n+sod(n) for n = 18844496 and 18844505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18844549) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31161 + ... + 31759.

It is an arithmetic number, because the mean of its divisors is an integer number (651700).

Almost surely, 2^18844540 is an apocalyptic number.

18844540 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 18844540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23461200).

18844540 is an abundant number, since it is smaller than the sum of its proper divisors (28077860).

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

18844540 is a wasteful number, since it uses less digits than its factorization.

18844540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 630 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 34.

The square root of 18844540 is about 4341.0298317335. The cubic root of 18844540 is about 266.1103994601.

The spelling of 18844540 in words is "eighteen million, eight hundred forty-four thousand, five hundred forty".