2781240 has 192 divisors, whose sum is σ = 10834560. Its totient is φ = 564480.

The previous prime is 2781221. The next prime is 2781271. The reversal of 2781240 is 421872.

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 2781240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 64659 + ... + 64701.

It is an arithmetic number, because the mean of its divisors is an integer number (56430).

2^2781240 is an apocalyptic number.

2781240 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 2781240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5417280).

2781240 is an abundant number, since it is smaller than the sum of its proper divisors (8053320).

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

2781240 is a wasteful number, since it uses less digits than its factorization.

2781240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 2781240 is about 1667.7050098863. The cubic root of 2781240 is about 140.6304896622.

The spelling of 2781240 in words is "two million, seven hundred eighty-one thousand, two hundred forty".