2859821 has 4 divisors (see below), whose sum is σ = 2863644. Its totient is φ = 2856000.

The previous prime is 2859803. The next prime is 2859847. The reversal of 2859821 is 1289582.

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 1562500 + 1297321 = 1250^2 + 1139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2859821 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 (2859121) 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, 380 + ... + 2421.

It is an arithmetic number, because the mean of its divisors is an integer number (715911).

2^2859821 is an apocalyptic number.

It is an amenable number.

2859821 is a deficient number, since it is larger than the sum of its proper divisors (3823).

2859821 is a wasteful number, since it uses less digits than its factorization.

2859821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3822.

The product of its digits is 11520, while the sum is 35.

The square root of 2859821 is about 1691.1005292412. The cubic root of 2859821 is about 141.9426634881.

The spelling of 2859821 in words is "two million, eight hundred fifty-nine thousand, eight hundred twenty-one".