4049561721 has 16 divisors (see below), whose sum is σ = 5722337664. Its totient is φ = 2538541824.

The previous prime is 4049561717. The next prime is 4049561741. The reversal of 4049561721 is 1271659404.

It is not a de Polignac number, because 4049561721 - 2² = 4049561717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4049561721.

It is not an unprimeable number, because it can be changed into a prime (4049561741) 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 15 ways as a sum of consecutive naturals, for example, 19420 + ... + 92066.

It is an arithmetic number, because the mean of its divisors is an integer number (357646104).

Almost surely, 2^4049561721 is an apocalyptic number.

It is an amenable number.

4049561721 is a deficient number, since it is larger than the sum of its proper divisors (1672775943).

4049561721 is a wasteful number, since it uses less digits than its factorization.

4049561721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73760.

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 4049561721 is about 63636.1667685916. The cubic root of 4049561721 is about 1593.9303528188.

The spelling of 4049561721 in words is "four billion, forty-nine million, five hundred sixty-one thousand, seven hundred twenty-one".