2877821 has 4 divisors (see below), whose sum is σ = 2881500. Its totient is φ = 2874144.

The previous prime is 2877817. The next prime is 2877839. The reversal of 2877821 is 1287782.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1464100 + 1413721 = 1210^2 + 1189^2 .

It is a cyclic number.

It is not a de Polignac number, because 2877821 - 2² = 2877817 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 (2877841) 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, 146 + ... + 2403.

It is an arithmetic number, because the mean of its divisors is an integer number (720375).

2^2877821 is an apocalyptic number.

It is an amenable number.

2877821 is a deficient number, since it is larger than the sum of its proper divisors (3679).

2877821 is a wasteful number, since it uses less digits than its factorization.

2877821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3678.

The product of its digits is 12544, while the sum is 35.

The square root of 2877821 is about 1696.4141593373. The cubic root of 2877821 is about 142.2398413185.

The spelling of 2877821 in words is "two million, eight hundred seventy-seven thousand, eight hundred twenty-one".