2640780 has 72 divisors (see below), whose sum is σ = 8491392. Its totient is φ = 662016.

The previous prime is 2640779. The next prime is 2640821. The reversal of 2640780 is 870462.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2629 + ... + 3491.

It is an arithmetic number, because the mean of its divisors is an integer number (117936).

2^2640780 is an apocalyptic number.

2640780 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 2640780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4245696).

2640780 is an abundant number, since it is smaller than the sum of its proper divisors (5850612).

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

2640780 is a wasteful number, since it uses less digits than its factorization.

2640780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895 (or 890 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 2640780 is about 1625.0476916078. The cubic root of 2640780 is about 138.2220746996. Note that the first 3 decimals are identical.

The spelling of 2640780 in words is "two million, six hundred forty thousand, seven hundred eighty".