8115039721 has 8 divisors (see below), whose sum is σ = 8270600904. Its totient is φ = 7959569280.

The previous prime is 8115039719. The next prime is 8115039727. The reversal of 8115039721 is 1279305118.

It can be written as a sum of positive squares in 4 ways, for example, as 6000051600 + 2114988121 = 77460^2 + 45989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8115039721 - 2¹ = 8115039719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8115039727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174061 + ... + 215701.

It is an arithmetic number, because the mean of its divisors is an integer number (1033825113).

Almost surely, 2^8115039721 is an apocalyptic number.

It is an amenable number.

8115039721 is a deficient number, since it is larger than the sum of its proper divisors (155561183).

8115039721 is a wasteful number, since it uses less digits than its factorization.

8115039721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45371.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 8115039721 is about 90083.5152566772. The cubic root of 8115039721 is about 2009.5410551715.

The spelling of 8115039721 in words is "eight billion, one hundred fifteen million, thirty-nine thousand, seven hundred twenty-one".