2818921 has 6 divisors (see below), whose sum is σ = 3279210. Its totient is φ = 2416176.

The previous prime is 2818909. The next prime is 2818939. The reversal of 2818921 is 1298182.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2706025 + 112896 = 1645^2 + 336^2 .

It is not a de Polignac number, because 2818921 - 2¹¹ = 2816873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2818421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28716 + ... + 28813.

It is an arithmetic number, because the mean of its divisors is an integer number (546535).

2^2818921 is an apocalyptic number.

It is an amenable number.

2818921 is a deficient number, since it is larger than the sum of its proper divisors (460289).

2818921 is an equidigital number, since it uses as much as digits as its factorization.

2818921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57543 (or 57536 counting only the distinct ones).

The product of its digits is 2304, while the sum is 31.

The square root of 2818921 is about 1678.9642640628. The cubic root of 2818921 is about 141.2627429963.

The spelling of 2818921 in words is "two million, eight hundred eighteen thousand, nine hundred twenty-one".