2745820 has 48 divisors (see below), whose sum is σ = 7193088. Its totient is φ = 855360.

The previous prime is 2745797. The next prime is 2745829. The reversal of 2745820 is 285472.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2745829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 649 + ... + 2431.

It is an arithmetic number, because the mean of its divisors is an integer number (149856).

2^2745820 is an apocalyptic number.

2745820 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 2745820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3596544).

2745820 is an abundant number, since it is smaller than the sum of its proper divisors (4447268).

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

2745820 is a wasteful number, since it uses less digits than its factorization.

2745820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810 (or 1808 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 2745820 is about 1657.0515984724. The cubic root of 2745820 is about 140.0309455403.

The spelling of 2745820 in words is "two million, seven hundred forty-five thousand, eight hundred twenty".