2541821 has 4 divisors (see below), whose sum is σ = 2629500. Its totient is φ = 2454144.

The previous prime is 2541817. The next prime is 2541829. The reversal of 2541821 is 1281452.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1125721 + 1416100 = 1061^2 + 1190^2 .

It is a cyclic number.

It is not a de Polignac number, because 2541821 - 2² = 2541817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2541829) 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, 43796 + ... + 43853.

It is an arithmetic number, because the mean of its divisors is an integer number (657375).

2^2541821 is an apocalyptic number.

It is an amenable number.

2541821 is a deficient number, since it is larger than the sum of its proper divisors (87679).

2541821 is an equidigital number, since it uses as much as digits as its factorization.

2541821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87678.

The product of its digits is 640, while the sum is 23.

The square root of 2541821 is about 1594.3089412031. The cubic root of 2541821 is about 136.4734973391.

The spelling of 2541821 in words is "two million, five hundred forty-one thousand, eight hundred twenty-one".