2787640 has 16 divisors (see below), whose sum is σ = 6272280. Its totient is φ = 1115040.

The previous prime is 2787619. The next prime is 2787649. The reversal of 2787640 is 467872.

It is a junction number, because it is equal to n+sod(n) for n = 2787596 and 2787605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2787649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34806 + ... + 34885.

2^2787640 is an apocalyptic number.

2787640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2787640 is an abundant number, since it is smaller than the sum of its proper divisors (3484640).

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

2787640 is a wasteful number, since it uses less digits than its factorization.

2787640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69702 (or 69698 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 2787640 is about 1669.6227118724. The cubic root of 2787640 is about 140.7382767942.

The spelling of 2787640 in words is "two million, seven hundred eighty-seven thousand, six hundred forty".