2785561 has 3 divisors (see below), whose sum is σ = 2787231. Its totient is φ = 2783892.

The previous prime is 2785513. The next prime is 2785577. The reversal of 2785561 is 1655872.

The square root of 2785561 is 1669.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1485961 + 1299600 = 1219^2 + 1140^2 .

It is not a de Polignac number, because 2785561 - 2¹¹ = 2783513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2785511) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 835 + ... + 2503.

It is an arithmetic number, because the mean of its divisors is an integer number (929077).

2^2785561 is an apocalyptic number.

2785561 is the 1669-th square number.

2785561 is the 835-th centered octagonal number.

It is an amenable number.

2785561 is a deficient number, since it is larger than the sum of its proper divisors (1670).

2785561 is an frugal number, since it uses more digits than its factorization.

2785561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3338 (or 1669 counting only the distinct ones).

The product of its digits is 16800, while the sum is 34.

The cubic root of 2785561 is about 140.7032809260.

The spelling of 2785561 in words is "two million, seven hundred eighty-five thousand, five hundred sixty-one".