2549821591 has 4 divisors (see below), whose sum is σ = 2550038400. Its totient is φ = 2549604784.

The previous prime is 2549821537. The next prime is 2549821601. The reversal of 2549821591 is 1951289452.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2549821591 - 2¹¹ = 2549819543 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 (2549821511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89686 + ... + 114643.

It is an arithmetic number, because the mean of its divisors is an integer number (637509600).

Almost surely, 2^2549821591 is an apocalyptic number.

2549821591 is a deficient number, since it is larger than the sum of its proper divisors (216809).

2549821591 is a wasteful number, since it uses less digits than its factorization.

2549821591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216808.

The product of its digits is 259200, while the sum is 46.

The square root of 2549821591 is about 50495.7581485812. The cubic root of 2549821591 is about 1366.1653456208.

It can be divided in two parts, 25498 and 21591, that added together give a square (47089 = 217²).

The spelling of 2549821591 in words is "two billion, five hundred forty-nine million, eight hundred twenty-one thousand, five hundred ninety-one".