2066640 has 80 divisors (see below), whose sum is σ = 6547200. Its totient is φ = 539136.

The previous prime is 2066609. The next prime is 2066641. The reversal of 2066640 is 466602.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2066640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2066641) 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, 18906 + ... + 19014.

It is an arithmetic number, because the mean of its divisors is an integer number (81840).

2^2066640 is an apocalyptic number.

2066640 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 2066640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3273600).

2066640 is an abundant number, since it is smaller than the sum of its proper divisors (4480560).

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

2066640 is a wasteful number, since it uses less digits than its factorization.

2066640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 2066640 is about 1437.5813020487. The cubic root of 2066640 is about 127.3761966262.

It can be divided in two parts, 20666 and 40, that added together give a triangular number (20706 = T₂₀₃).

The spelling of 2066640 in words is "two million, sixty-six thousand, six hundred forty".