18208740 has 96 divisors (see below), whose sum is σ = 56899584. Its totient is φ = 4312960.

The previous prime is 18208727. The next prime is 18208747. The reversal of 18208740 is 4780281.

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 = 18208698 and 18208707.

It is not an unprimeable number, because it can be changed into a prime (18208747) 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, 30727 + ... + 31313.

It is an arithmetic number, because the mean of its divisors is an integer number (592704).

Almost surely, 2^18208740 is an apocalyptic number.

18208740 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 18208740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28449792).

18208740 is an abundant number, since it is smaller than the sum of its proper divisors (38690844).

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

18208740 is a wasteful number, since it uses less digits than its factorization.

18208740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18208740 is about 4267.1700223919. The cubic root of 18208740 is about 263.0833105546.

The spelling of 18208740 in words is "eighteen million, two hundred eight thousand, seven hundred forty".