18047640 has 128 divisors (see below), whose sum is σ = 60963840. Its totient is φ = 4240896.

The previous prime is 18047593. The next prime is 18047647. The reversal of 18047640 is 4674081.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 18047598 and 18047607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18047647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35629 + ... + 36131.

It is an arithmetic number, because the mean of its divisors is an integer number (476280).

Almost surely, 2^18047640 is an apocalyptic number.

18047640 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 18047640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30481920).

18047640 is an abundant number, since it is smaller than the sum of its proper divisors (42916200).

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

18047640 is a wasteful number, since it uses less digits than its factorization.

18047640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553 (or 549 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 18047640 is about 4248.2514049901. The cubic root of 18047640 is about 262.3051433734.

The spelling of 18047640 in words is "eighteen million, forty-seven thousand, six hundred forty".