2722721 has 4 divisors (see below), whose sum is σ = 2726532. Its totient is φ = 2718912.

The previous prime is 2722691. The next prime is 2722729. The reversal of 2722721 is 1272272.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1488400 + 1234321 = 1220^2 + 1111^2 .

It is a cyclic number.

It is not a de Polignac number, because 2722721 - 2¹⁴ = 2706337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2722729) 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, 476 + ... + 2381.

It is an arithmetic number, because the mean of its divisors is an integer number (681633).

2^2722721 is an apocalyptic number.

2722721 is the 953-rd octagonal number.

It is an amenable number.

2722721 is a deficient number, since it is larger than the sum of its proper divisors (3811).

2722721 is an equidigital number, since it uses as much as digits as its factorization.

2722721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3810.

The product of its digits is 784, while the sum is 23.

The square root of 2722721 is about 1650.0669683380. The cubic root of 2722721 is about 139.6371727457.

Adding to 2722721 its reverse (1272272), we get a palindrome (3994993).

It can be divided in two parts, 2722 and 721, that added together give a palindrome (3443).

The spelling of 2722721 in words is "two million, seven hundred twenty-two thousand, seven hundred twenty-one".