2549681 has 4 divisors (see below), whose sum is σ = 2585664. Its totient is φ = 2513700.

The previous prime is 2549669. The next prime is 2549683. The reversal of 2549681 is 1869452.

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 a de Polignac number, because none of the positive numbers 2^k-2549681 is a prime.

It is a super-2 number, since 2×2549681² = 13001746403522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2549683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17885 + ... + 18026.

It is an arithmetic number, because the mean of its divisors is an integer number (646416).

2^2549681 is an apocalyptic number.

It is an amenable number.

2549681 is a deficient number, since it is larger than the sum of its proper divisors (35983).

2549681 is an equidigital number, since it uses as much as digits as its factorization.

2549681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35982.

The product of its digits is 17280, while the sum is 35.

The square root of 2549681 is about 1596.7720563687. The cubic root of 2549681 is about 136.6140236141.

The spelling of 2549681 in words is "two million, five hundred forty-nine thousand, six hundred eighty-one".