2561855 has 8 divisors (see below), whose sum is σ = 3208032. Its totient is φ = 1960288.

The previous prime is 2561833. The next prime is 2561857. The reversal of 2561855 is 5581652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2561855 - 2¹⁸ = 2299711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11024 + ... + 11253.

It is an arithmetic number, because the mean of its divisors is an integer number (401004).

2^2561855 is an apocalyptic number.

2561855 is a deficient number, since it is larger than the sum of its proper divisors (646177).

2561855 is a wasteful number, since it uses less digits than its factorization.

2561855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22305.

The product of its digits is 12000, while the sum is 32.

The square root of 2561855 is about 1600.5795825263. The cubic root of 2561855 is about 136.8311094793.

The spelling of 2561855 in words is "two million, five hundred sixty-one thousand, eight hundred fifty-five".