2559781 has 4 divisors (see below), whose sum is σ = 2925472. Its totient is φ = 2194092.

The previous prime is 2559773. The next prime is 2559787. The reversal of 2559781 is 1879552.

2559781 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2559781 - 2³ = 2559773 is a prime.

It is a super-2 number, since 2×2559781² = 13104957535922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2559781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2559787) 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 3 ways as a sum of consecutive naturals, for example, 182835 + ... + 182848.

It is an arithmetic number, because the mean of its divisors is an integer number (731368).

2^2559781 is an apocalyptic number.

It is an amenable number.

2559781 is a deficient number, since it is larger than the sum of its proper divisors (365691).

2559781 is an equidigital number, since it uses as much as digits as its factorization.

2559781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365690.

The product of its digits is 25200, while the sum is 37.

The square root of 2559781 is about 1599.9315610363. The cubic root of 2559781 is about 136.7941747403.

The spelling of 2559781 in words is "two million, five hundred fifty-nine thousand, seven hundred eighty-one".