2780000 has 60 divisors (see below), whose sum is σ = 6888420. Its totient is φ = 1104000.

The previous prime is 2779991. The next prime is 2780039. The reversal of 2780000 is 872.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 19931 + ... + 20069.

It is an arithmetic number, because the mean of its divisors is an integer number (114807).

2^2780000 is an apocalyptic number.

2780000 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 2780000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3444210).

2780000 is an abundant number, since it is smaller than the sum of its proper divisors (4108420).

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

2780000 is an equidigital number, since it uses as much as digits as its factorization.

2780000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 2780000 is about 1667.3332000533. Note that the first 3 decimals coincide. The cubic root of 2780000 is about 140.6095867881.

Adding to 2780000 its reverse (872), we get a palindrome (2780872).

The spelling of 2780000 in words is "two million, seven hundred eighty thousand".