2171680 has 72 divisors (see below), whose sum is σ = 5989788. Its totient is φ = 741888.

The previous prime is 2171657. The next prime is 2171707. The reversal of 2171680 is 861712.

2171680 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 2039184 + 132496 = 1428^2 + 364^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7702 + ... + 7978.

2^2171680 is an apocalyptic number.

2171680 is a gapful number since it is divisible by the number (20) 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 2171680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2994894).

2171680 is an abundant number, since it is smaller than the sum of its proper divisors (3818108).

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

2171680 is a wasteful number, since it uses less digits than its factorization.

2171680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 2171680 is about 1473.6621050974. The cubic root of 2171680 is about 129.4986608091.

The spelling of 2171680 in words is "two million, one hundred seventy-one thousand, six hundred eighty".