18905680 has 60 divisors (see below), whose sum is σ = 45685692. Its totient is φ = 7275520.

The previous prime is 18905671. The next prime is 18905687. The reversal of 18905680 is 8650981.

It can be written as a sum of positive squares in 6 ways, for example, as 35344 + 18870336 = 188^2 + 4344^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18905687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67140 + ... + 67420.

Almost surely, 2^18905680 is an apocalyptic number.

18905680 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 18905680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22842846).

18905680 is an abundant number, since it is smaller than the sum of its proper divisors (26780012).

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

18905680 is a wasteful number, since it uses less digits than its factorization.

18905680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 18905680 is about 4348.0662368460. The cubic root of 18905680 is about 266.3978819492.

The spelling of 18905680 in words is "eighteen million, nine hundred five thousand, six hundred eighty".