2561818 has 12 divisors (see below), whose sum is σ = 4470282. Its totient is φ = 1097880.

The previous prime is 2561813. The next prime is 2561821. The reversal of 2561818 is 8181652.

2561818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1979649 + 582169 = 1407^2 + 763^2 .

It is a super-2 number, since 2×2561818² = 13125822930248, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

2561818 is a modest number, since divided by 1818 gives 256 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 2561818.

It is not an unprimeable number, because it can be changed into a prime (2561813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12973 + ... + 13168.

2^2561818 is an apocalyptic number.

2561818 is a deficient number, since it is larger than the sum of its proper divisors (1908464).

2561818 is a wasteful number, since it uses less digits than its factorization.

2561818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26157 (or 26150 counting only the distinct ones).

The product of its digits is 3840, while the sum is 31.

The square root of 2561818 is about 1600.5680241714. The cubic root of 2561818 is about 136.8304507411.

The spelling of 2561818 in words is "two million, five hundred sixty-one thousand, eight hundred eighteen".