2889721 has 4 divisors (see below), whose sum is σ = 2960244. Its totient is φ = 2819200.

The previous prime is 2889707. The next prime is 2889739. The reversal of 2889721 is 1279882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1279882 = 2 ⋅639941.

It can be written as a sum of positive squares in 2 ways, for example, as 1590121 + 1299600 = 1261^2 + 1140^2 .

It is a cyclic number.

It is not a de Polignac number, because 2889721 - 2⁹ = 2889209 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 (2889781) 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 in 3 ways as a sum of consecutive naturals, for example, 35200 + ... + 35281.

It is an arithmetic number, because the mean of its divisors is an integer number (740061).

2^2889721 is an apocalyptic number.

It is an amenable number.

2889721 is a deficient number, since it is larger than the sum of its proper divisors (70523).

2889721 is an equidigital number, since it uses as much as digits as its factorization.

2889721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70522.

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

The square root of 2889721 is about 1699.9179391959. The cubic root of 2889721 is about 142.4356290776.

The spelling of 2889721 in words is "two million, eight hundred eighty-nine thousand, seven hundred twenty-one".