2731780 has 24 divisors (see below), whose sum is σ = 5784408. Its totient is φ = 1083648.

The previous prime is 2731753. The next prime is 2731783. The reversal of 2731780 is 871372.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 788544 + 1943236 = 888^2 + 1394^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (2731783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2242 + ... + 3238.

It is an arithmetic number, because the mean of its divisors is an integer number (241017).

2^2731780 is an apocalyptic number.

2731780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2731780 is an abundant number, since it is smaller than the sum of its proper divisors (3052628).

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

2731780 is a wasteful number, since it uses less digits than its factorization.

2731780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1143 (or 1141 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 2731780 is about 1652.8097289162. The cubic root of 2731780 is about 139.7918676020.

The spelling of 2731780 in words is "two million, seven hundred thirty-one thousand, seven hundred eighty".