8721309449 has 8 divisors (see below), whose sum is σ = 8826218280. Its totient is φ = 8616554496.

The previous prime is 8721309413. The next prime is 8721309473. The reversal of 8721309449 is 9449031278.

It can be written as a sum of positive squares in 4 ways, for example, as 5075565049 + 3645744400 = 71243^2 + 60380^2 .

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 8721309449 - 2⁸ = 8721309193 is a prime.

It is a super-2 number, since 2×8721309449² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8721309409) 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, 77657 + ... + 153209.

It is an arithmetic number, because the mean of its divisors is an integer number (1103277285).

Almost surely, 2^8721309449 is an apocalyptic number.

8721309449 is a gapful number since it is divisible by the number (89) formed by its first and last digit.

It is an amenable number.

8721309449 is a deficient number, since it is larger than the sum of its proper divisors (104908831).

8721309449 is a wasteful number, since it uses less digits than its factorization.

8721309449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76939.

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 8721309449 is about 93387.9513052942. The cubic root of 8721309449 is about 2058.3879562412.

The spelling of 8721309449 in words is "eight billion, seven hundred twenty-one million, three hundred nine thousand, four hundred forty-nine".