4518821 has 4 divisors (see below), whose sum is σ = 4784652. Its totient is φ = 4252992.

The previous prime is 4518803. The next prime is 4518823. The reversal of 4518821 is 1288154.

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 3045025 + 1473796 = 1745^2 + 1214^2 .

It is not a de Polignac number, because 4518821 - 2¹⁴ = 4502437 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 (4518823) 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, 132890 + ... + 132923.

It is an arithmetic number, because the mean of its divisors is an integer number (1196163).

Almost surely, 2^4518821 is an apocalyptic number.

It is an amenable number.

4518821 is a deficient number, since it is larger than the sum of its proper divisors (265831).

4518821 is a wasteful number, since it uses less digits than its factorization.

4518821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265830.

The product of its digits is 2560, while the sum is 29.

The square root of 4518821 is about 2125.7518669873. The cubic root of 4518821 is about 165.3262110868.

The spelling of 4518821 in words is "four million, five hundred eighteen thousand, eight hundred twenty-one".