9988621 has 4 divisors (see below), whose sum is σ = 10001500. Its totient is φ = 9975744.

The previous prime is 9988609. The next prime is 9988633. The reversal of 9988621 is 1268899.

It is a happy number.

9988621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (9988609) and next prime (9988633).

It can be written as a sum of positive squares in 2 ways, for example, as 6325225 + 3663396 = 2515^2 + 1914^2 .

It is a cyclic number.

It is not a de Polignac number, because 9988621 - 2⁹ = 9988109 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9988691) 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, 5196 + ... + 6853.

It is an arithmetic number, because the mean of its divisors is an integer number (2500375).

Almost surely, 2^9988621 is an apocalyptic number.

It is an amenable number.

9988621 is a deficient number, since it is larger than the sum of its proper divisors (12879).

9988621 is a wasteful number, since it uses less digits than its factorization.

9988621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12878.

The product of its digits is 62208, while the sum is 43.

The square root of 9988621 is about 3160.4779701811. The cubic root of 9988621 is about 215.3617202803.

It can be divided in two parts, 9988 and 621, that added together give a square (10609 = 103²).

The spelling of 9988621 in words is "nine million, nine hundred eighty-eight thousand, six hundred twenty-one".