2780749 has 4 divisors (see below), whose sum is σ = 2814336. Its totient is φ = 2747164.

The previous prime is 2780719. The next prime is 2780753. The reversal of 2780749 is 9470872.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2780749 - 2⁷ = 2780621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2780719) 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, 16669 + ... + 16834.

It is an arithmetic number, because the mean of its divisors is an integer number (703584).

2^2780749 is an apocalyptic number.

It is an amenable number.

2780749 is a deficient number, since it is larger than the sum of its proper divisors (33587).

2780749 is an equidigital number, since it uses as much as digits as its factorization.

2780749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33586.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 2780749 is about 1667.5577951004. The cubic root of 2780749 is about 140.6222135415.

The spelling of 2780749 in words is "two million, seven hundred eighty thousand, seven hundred forty-nine".