2821660 has 48 divisors (see below), whose sum is σ = 6453216. Its totient is φ = 1032192.

The previous prime is 2821649. The next prime is 2821681. The reversal of 2821660 is 661282.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14524 + ... + 14716.

It is an arithmetic number, because the mean of its divisors is an integer number (134442).

2^2821660 is an apocalyptic number.

2821660 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 2821660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3226608).

2821660 is an abundant number, since it is smaller than the sum of its proper divisors (3631556).

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

2821660 is a wasteful number, since it uses less digits than its factorization.

2821660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 2821660 is about 1679.7797474669. The cubic root of 2821660 is about 141.3084807573.

It can be divided in two parts, 2821 and 660, that added together give a square (3481 = 59²).

The spelling of 2821660 in words is "two million, eight hundred twenty-one thousand, six hundred sixty".