8999621 has 4 divisors (see below), whose sum is σ = 9242892. Its totient is φ = 8756352.

The previous prime is 8999609. The next prime is 8999651. The reversal of 8999621 is 1269998.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7230721 + 1768900 = 2689^2 + 1330^2 .

It is a cyclic number.

It is not a de Polignac number, because 8999621 - 2¹⁴ = 8983237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8999651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121580 + ... + 121653.

It is an arithmetic number, because the mean of its divisors is an integer number (2310723).

Almost surely, 2^8999621 is an apocalyptic number.

It is an amenable number.

8999621 is a deficient number, since it is larger than the sum of its proper divisors (243271).

8999621 is a wasteful number, since it uses less digits than its factorization.

8999621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243270.

The product of its digits is 69984, while the sum is 44.

The square root of 8999621 is about 2999.9368326683. The cubic root of 8999621 is about 208.0054624428.

The spelling of 8999621 in words is "eight million, nine hundred ninety-nine thousand, six hundred twenty-one".