2721289 has 4 divisors (see below), whose sum is σ = 2724624. Its totient is φ = 2717956.

The previous prime is 2721259. The next prime is 2721307. The reversal of 2721289 is 9821272.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2721289 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

2721289 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2721289.

It is not an unprimeable number, because it can be changed into a prime (2721259) 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, 474 + ... + 2380.

It is an arithmetic number, because the mean of its divisors is an integer number (681156).

2^2721289 is an apocalyptic number.

It is an amenable number.

2721289 is a deficient number, since it is larger than the sum of its proper divisors (3335).

2721289 is a wasteful number, since it uses less digits than its factorization.

2721289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3334.

The product of its digits is 4032, while the sum is 31.

The square root of 2721289 is about 1649.6329894858. The cubic root of 2721289 is about 139.6126879873.

It can be divided in two parts, 27 and 21289, that added together give a square (21316 = 146²).

The spelling of 2721289 in words is "two million, seven hundred twenty-one thousand, two hundred eighty-nine".