2210656721 has 12 divisors (see below), whose sum is σ = 2735759232. Its totient is φ = 1749090096.

The previous prime is 2210656711. The next prime is 2210656739. The reversal of 2210656721 is 1276560122.

2210656721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2210656721 - 2¹⁸ = 2210394577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2210656711) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 933161 + ... + 935526.

It is an arithmetic number, because the mean of its divisors is an integer number (227979936).

Almost surely, 2^2210656721 is an apocalyptic number.

It is an amenable number.

2210656721 is a deficient number, since it is larger than the sum of its proper divisors (525102511).

2210656721 is a wasteful number, since it uses less digits than its factorization.

2210656721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1868720 (or 1868707 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 2210656721 is about 47017.6213881562. The cubic root of 2210656721 is about 1302.6880712507.

The spelling of 2210656721 in words is "two billion, two hundred ten million, six hundred fifty-six thousand, seven hundred twenty-one".