2809680 has 80 divisors (see below), whose sum is σ = 9106560. Its totient is φ = 715264.

The previous prime is 2809679. The next prime is 2809687. The reversal of 2809680 is 869082.

It is a tau number, because it is divible by the number of its divisors (80).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2809687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5266 + ... + 5774.

It is an arithmetic number, because the mean of its divisors is an integer number (113832).

2^2809680 is an apocalyptic number.

2809680 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 2809680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4553280).

2809680 is an abundant number, since it is smaller than the sum of its proper divisors (6296880).

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

2809680 is a wasteful number, since it uses less digits than its factorization.

2809680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548 (or 542 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 2809680 is about 1676.2100107087. The cubic root of 2809680 is about 141.1082112828.

The spelling of 2809680 in words is "two million, eight hundred nine thousand, six hundred eighty".