2543681 has 8 divisors (see below), whose sum is σ = 2978304. Its totient is φ = 2126880.

The previous prime is 2543657. The next prime is 2543699. The reversal of 2543681 is 1863452.

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

It is not a de Polignac number, because 2543681 - 2⁶ = 2543617 is a prime.

It is a super-2 number, since 2×2543681² = 12940626059522, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2¹⁹ + 5⁹ + 4⁸ + 3 + 6³ + 8³ + 1 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2543621) 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, 4145 + ... + 4718.

It is an arithmetic number, because the mean of its divisors is an integer number (372288).

2^2543681 is an apocalyptic number.

It is an amenable number.

2543681 is a deficient number, since it is larger than the sum of its proper divisors (434623).

2543681 is an equidigital number, since it uses as much as digits as its factorization.

2543681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8911.

The product of its digits is 5760, while the sum is 29.

The square root of 2543681 is about 1594.8921593638. The cubic root of 2543681 is about 136.5067777856.

It can be divided in two parts, 25 and 43681, that multiplied together give a square (1092025 = 1045²).

The spelling of 2543681 in words is "two million, five hundred forty-three thousand, six hundred eighty-one".