2780003 has 4 divisors (see below), whose sum is σ = 2839200. Its totient is φ = 2720808.

The previous prime is 2779991. The next prime is 2780039. The reversal of 2780003 is 3000872.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2780003 - 2⁶ = 2779939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2780053) 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, 29528 + ... + 29621.

It is an arithmetic number, because the mean of its divisors is an integer number (709800).

2^2780003 is an apocalyptic number.

2780003 is a deficient number, since it is larger than the sum of its proper divisors (59197).

2780003 is an equidigital number, since it uses as much as digits as its factorization.

2780003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59196.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 2780003 is about 1667.3340996933. The cubic root of 2780003 is about 140.6096373670.

Adding to 2780003 its reverse (3000872), we get a palindrome (5780875).

It can be divided in two parts, 27 and 80003, that multiplied together give a triangular number (2160081 = T₂₀₇₈).

The spelling of 2780003 in words is "two million, seven hundred eighty thousand, three".