99000721 has 4 divisors (see below), whose sum is σ = 99723492. Its totient is φ = 98277952.

The previous prime is 99000719. The next prime is 99000739. The reversal of 99000721 is 12700099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12700099 = 743 ⋅17093.

It can be written as a sum of positive squares in 2 ways, for example, as 34680321 + 64320400 = 5889^2 + 8020^2 .

It is a cyclic number.

It is not a de Polignac number, because 99000721 - 2¹ = 99000719 is a prime.

It is a super-2 number, since 2×99000721² = 19602285517039682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 99000721.

It is not an unprimeable number, because it can be changed into a prime (99000791) 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, 361180 + ... + 361453.

It is an arithmetic number, because the mean of its divisors is an integer number (24930873).

Almost surely, 2^99000721 is an apocalyptic number.

It is an amenable number.

99000721 is a deficient number, since it is larger than the sum of its proper divisors (722771).

99000721 is a wasteful number, since it uses less digits than its factorization.

99000721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722770.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 99000721 is about 9949.9106026135. The cubic root of 99000721 is about 462.6076239435.

The spelling of 99000721 in words is "ninety-nine million, seven hundred twenty-one", and thus it is an aban number.