2720640 has 128 divisors (see below), whose sum is σ = 9424800. Its totient is φ = 663552.

The previous prime is 2720623. The next prime is 2720671. The reversal of 2720640 is 460272.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24906 + ... + 25014.

2^2720640 is an apocalyptic number.

2720640 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 2720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4712400).

2720640 is an abundant number, since it is smaller than the sum of its proper divisors (6704160).

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

2720640 is a wasteful number, since it uses less digits than its factorization.

2720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 2720640 is about 1649.4362673350. The cubic root of 2720640 is about 139.6015883652.

The spelling of 2720640 in words is "two million, seven hundred twenty thousand, six hundred forty".