8047721 has 4 divisors (see below), whose sum is σ = 8779344. Its totient is φ = 7316100.

The previous prime is 8047717. The next prime is 8047727. The reversal of 8047721 is 1277408.

8047721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8047721 - 2² = 8047717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8047727) 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 3 ways as a sum of consecutive naturals, for example, 365795 + ... + 365816.

It is an arithmetic number, because the mean of its divisors is an integer number (2194836).

Almost surely, 2^8047721 is an apocalyptic number.

It is an amenable number.

8047721 is a deficient number, since it is larger than the sum of its proper divisors (731623).

8047721 is a wasteful number, since it uses less digits than its factorization.

8047721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731622.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 8047721 is about 2836.8505424150. The cubic root of 8047721 is about 200.3968868830.

The spelling of 8047721 in words is "eight million, forty-seven thousand, seven hundred twenty-one".