201680 has 20 divisors (see below), whose sum is σ = 469092. Its totient is φ = 80640.

The previous prime is 201673. The next prime is 201683. The reversal of 201680 is 86102.

It can be written as a sum of positive squares in 2 ways, for example, as 21904 + 179776 = 148^2 + 424^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (17) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201683) by changing a digit.

201680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1181 + ... + 1340.

2²⁰¹⁶⁸⁰ is an apocalyptic number.

201680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201680 is an abundant number, since it is smaller than the sum of its proper divisors (267412).

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

201680 is a wasteful number, since it uses less digits than its factorization.

201680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2534 (or 2528 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 201680 is about 449.0879646573. The cubic root of 201680 is about 58.6436433993.

Adding to 201680 its reverse (86102), we get a palindrome (287782).

The spelling of 201680 in words is "two hundred one thousand, six hundred eighty".