8071721 has 6 divisors (see below), whose sum is σ = 9389610. Its totient is φ = 6918576.

The previous prime is 8071709. The next prime is 8071727. The reversal of 8071721 is 1271708.

It can be written as a sum of positive squares in only one way, i.e., 6817321 + 1254400 = 2611^2 + 1120^2 .

It is not a de Polignac number, because 8071721 - 2¹⁴ = 8055337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8071727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 82316 + ... + 82413.

It is an arithmetic number, because the mean of its divisors is an integer number (1564935).

Almost surely, 2^8071721 is an apocalyptic number.

It is an amenable number.

8071721 is a deficient number, since it is larger than the sum of its proper divisors (1317889).

8071721 is a wasteful number, since it uses less digits than its factorization.

8071721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164743 (or 164736 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 8071721 is about 2841.0774364667. The cubic root of 8071721 is about 200.5958977659.

The spelling of 8071721 in words is "eight million, seventy-one thousand, seven hundred twenty-one".