2509866 has 20 divisors (see below), whose sum is σ = 5624322. Its totient is φ = 836568.

The previous prime is 2509861. The next prime is 2509891. The reversal of 2509866 is 6689052.

It can be written as a sum of positive squares in only one way, i.e., 2480625 + 29241 = 1575^2 + 171^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 2509866.

It is not an unprimeable number, because it can be changed into a prime (2509861) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 7585 + ... + 7908.

2^2509866 is an apocalyptic number.

2509866 is an abundant number, since it is smaller than the sum of its proper divisors (3114456).

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

2509866 is a wasteful number, since it uses less digits than its factorization.

2509866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15507 (or 15498 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 2509866 is about 1584.2556611860. The cubic root of 2509866 is about 135.8991827795.

It can be divided in two parts, 2509 and 866, that added together give a cube (3375 = 15³).

The spelling of 2509866 in words is "two million, five hundred nine thousand, eight hundred sixty-six".