2511721 has 2 divisors, whose sum is σ = 2511722. Its totient is φ = 2511720.

The previous prime is 2511709. The next prime is 2511749. The reversal of 2511721 is 1271152.

2511721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1590121 + 921600 = 1261^2 + 960^2 .

It is a cyclic number.

It is not a de Polignac number, because 2511721 - 2¹⁵ = 2478953 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (2511791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1255860 + 1255861.

It is an arithmetic number, because the mean of its divisors is an integer number (1255861).

2^2511721 is an apocalyptic number.

It is an amenable number.

2511721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2511721 is an equidigital number, since it uses as much as digits as its factorization.

2511721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 140, while the sum is 19.

The square root of 2511721 is about 1584.8410014888. The cubic root of 2511721 is about 135.9326548059.

Adding to 2511721 its reverse (1271152), we get a palindrome (3782873).

The spelling of 2511721 in words is "two million, five hundred eleven thousand, seven hundred twenty-one".