2561842 has 4 divisors (see below), whose sum is σ = 3842766. Its totient is φ = 1280920.

The previous prime is 2561833. The next prime is 2561857. The reversal of 2561842 is 2481652.

2561842 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 2556801 + 5041 = 1599^2 + 71^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2561842.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 640459 + ... + 640462.

2^2561842 is an apocalyptic number.

2561842 is a deficient number, since it is larger than the sum of its proper divisors (1280924).

2561842 is a wasteful number, since it uses less digits than its factorization.

2561842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280923.

The product of its digits is 3840, while the sum is 28.

The square root of 2561842 is about 1600.5755214922. The cubic root of 2561842 is about 136.8308780314.

It can be divided in two parts, 2561 and 842, that added together give a triangular number (3403 = T₈₂).

The spelling of 2561842 in words is "two million, five hundred sixty-one thousand, eight hundred forty-two".