4051072721 has 4 divisors (see below), whose sum is σ = 4051214244. Its totient is φ = 4050931200.

The previous prime is 4051072703. The next prime is 4051072733. The reversal of 4051072721 is 1272701504.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1280208400 + 2770864321 = 35780^2 + 52639^2 .

It is a cyclic number.

It is not a de Polignac number, because 4051072721 - 2¹⁰ = 4051071697 is a prime.

It is a super-2 number, since 2×4051072721² = 32822380381660687682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4051072771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11000 + ... + 90681.

It is an arithmetic number, because the mean of its divisors is an integer number (1012803561).

Almost surely, 2^4051072721 is an apocalyptic number.

It is an amenable number.

4051072721 is a deficient number, since it is larger than the sum of its proper divisors (141523).

4051072721 is a wasteful number, since it uses less digits than its factorization.

4051072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141522.

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 4051072721 is about 63648.0378409264. The cubic root of 4051072721 is about 1594.1285742101.

The spelling of 4051072721 in words is "four billion, fifty-one million, seventy-two thousand, seven hundred twenty-one".