8072721 has 12 divisors (see below), whose sum is σ = 11728080. Its totient is φ = 5350680.

The previous prime is 8072717. The next prime is 8072737. The reversal of 8072721 is 1272708.

8072721 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8072721 - 2² = 8072717 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (8072761) 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, 895 + ... + 4116.

It is an arithmetic number, because the mean of its divisors is an integer number (977340).

Almost surely, 2^8072721 is an apocalyptic number.

It is an amenable number.

8072721 is a deficient number, since it is larger than the sum of its proper divisors (3655359).

8072721 is a wasteful number, since it uses less digits than its factorization.

8072721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5196 (or 5193 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 8072721 is about 2841.2534205875. The cubic root of 8072721 is about 200.6041813201.

The spelling of 8072721 in words is "eight million, seventy-two thousand, seven hundred twenty-one".