2011056721 has 2 divisors, whose sum is σ = 2011056722. Its totient is φ = 2011056720.

The previous prime is 2011056709. The next prime is 2011056731. The reversal of 2011056721 is 1276501102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1250400321 + 760656400 = 35361^2 + 27580^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011056721 - 2¹⁵ = 2011023953 is a prime.

It is not a weakly prime, because it can be changed into another prime (2011056731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005528360 + 1005528361.

It is an arithmetic number, because the mean of its divisors is an integer number (1005528361).

Almost surely, 2^2011056721 is an apocalyptic number.

It is an amenable number.

2011056721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011056721 is an equidigital number, since it uses as much as digits as its factorization.

2011056721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 2011056721 is about 44844.8070683775. The cubic root of 2011056721 is about 1262.2385503894.

Adding to 2011056721 its reverse (1276501102), we get a palindrome (3287557823).

The spelling of 2011056721 in words is "two billion, eleven million, fifty-six thousand, seven hundred twenty-one".