2127721 has 2 divisors, whose sum is σ = 2127722. Its totient is φ = 2127720.

The previous prime is 2127691. The next prime is 2127733. The reversal of 2127721 is 1277212.

2127721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is the 596-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1290496 + 837225 = 1136^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 2127721 - 2⁵ = 2127689 is a prime.

2127721 is a lucky number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 2127692 and 2127701.

It is not a weakly prime, because it can be changed into another prime (2127751) 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, 1063860 + 1063861.

It is an arithmetic number, because the mean of its divisors is an integer number (1063861).

2^2127721 is an apocalyptic number.

It is an amenable number.

2127721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2127721 is an equidigital number, since it uses as much as digits as its factorization.

2127721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 392, while the sum is 22.

The square root of 2127721 is about 1458.6709704385. The cubic root of 2127721 is about 128.6189303022.

The spelling of 2127721 in words is "two million, one hundred twenty-seven thousand, seven hundred twenty-one".