18181040 has 80 divisors (see below), whose sum is σ = 45372096. Its totient is φ = 6758400.

The previous prime is 18181039. The next prime is 18181103. The reversal of 18181040 is 4018181.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a junction number, because it is equal to n+sod(n) for n = 18180997 and 18181015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75320 + ... + 75560.

Almost surely, 2^18181040 is an apocalyptic number.

18181040 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 18181040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22686048).

18181040 is an abundant number, since it is smaller than the sum of its proper divisors (27191056).

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

18181040 is a wasteful number, since it uses less digits than its factorization.

18181040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 18181040 is about 4263.9230762292. The cubic root of 18181040 is about 262.9498379082.

The spelling of 18181040 in words is "eighteen million, one hundred eighty-one thousand, forty".