8239099721 has 16 divisors (see below), whose sum is σ = 8687720448. Its totient is φ = 7798362000.

The previous prime is 8239099717. The next prime is 8239099733. The reversal of 8239099721 is 1279909328.

It is a cyclic number.

It is not a de Polignac number, because 8239099721 - 2² = 8239099717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8239099721.

It is not an unprimeable number, because it can be changed into a prime (8239099021) 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, 1102046 + ... + 1109496.

It is an arithmetic number, because the mean of its divisors is an integer number (542982528).

Almost surely, 2^8239099721 is an apocalyptic number.

It is an amenable number.

8239099721 is a deficient number, since it is larger than the sum of its proper divisors (448620727).

8239099721 is a wasteful number, since it uses less digits than its factorization.

8239099721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7972.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 8239099721 is about 90769.4867287460. The cubic root of 8239099721 is about 2019.7297060977.

The spelling of 8239099721 in words is "eight billion, two hundred thirty-nine million, ninety-nine thousand, seven hundred twenty-one".