2987821 has 2 divisors, whose sum is σ = 2987822. Its totient is φ = 2987820.

The previous prime is 2987791. The next prime is 2987827. The reversal of 2987821 is 1287892.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1653796 + 1334025 = 1286^2 + 1155^2 .

It is a cyclic number.

It is not a de Polignac number, because 2987821 - 2¹⁵ = 2955053 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2987827) 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 as a sum of consecutive naturals, namely, 1493910 + 1493911.

It is an arithmetic number, because the mean of its divisors is an integer number (1493911).

2^2987821 is an apocalyptic number.

It is an amenable number.

2987821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2987821 is an equidigital number, since it uses as much as digits as its factorization.

2987821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 37.

The square root of 2987821 is about 1728.5314576252. The cubic root of 2987821 is about 144.0295239104.

The spelling of 2987821 in words is "two million, nine hundred eighty-seven thousand, eight hundred twenty-one".