2561819 has 4 divisors (see below), whose sum is σ = 2758896. Its totient is φ = 2364744.

The previous prime is 2561813. The next prime is 2561821. The reversal of 2561819 is 9181652.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2561819 is a prime.

It is a super-2 number, since 2×2561819² = 13125833177522, which contains 22 as substring.

It is a Duffinian number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98519 + ... + 98544.

It is an arithmetic number, because the mean of its divisors is an integer number (689724).

2^2561819 is an apocalyptic number.

2561819 is a deficient number, since it is larger than the sum of its proper divisors (197077).

2561819 is a wasteful number, since it uses less digits than its factorization.

2561819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197076.

The product of its digits is 4320, while the sum is 32.

The square root of 2561819 is about 1600.5683365605. The cubic root of 2561819 is about 136.8304685449.

The spelling of 2561819 in words is "two million, five hundred sixty-one thousand, eight hundred nineteen".