10721721 has 16 divisors (see below), whose sum is σ = 14598144. Its totient is φ = 6998544.

The previous prime is 10721653. The next prime is 10721723. The reversal of 10721721 is 12712701.

It is a happy number.

10721721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-10721721 is a prime.

It is a super-2 number, since 2×10721721² = 229910602403682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (10721723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40636 + ... + 40898.

It is an arithmetic number, because the mean of its divisors is an integer number (912384).

Almost surely, 2^10721721 is an apocalyptic number.

It is an amenable number.

10721721 is a deficient number, since it is larger than the sum of its proper divisors (3876423).

10721721 is a wasteful number, since it uses less digits than its factorization.

10721721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500.

The product of its (nonzero) digits is 196, while the sum is 21.

The square root of 10721721 is about 3274.4039152188. The cubic root of 10721721 is about 220.5065531446.

The spelling of 10721721 in words is "ten million, seven hundred twenty-one thousand, seven hundred twenty-one".