9911621 has 4 divisors (see below), whose sum is σ = 9918144. Its totient is φ = 9905100.

The previous prime is 9911609. The next prime is 9911623. The reversal of 9911621 is 1261199.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9911621 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 (9911623) 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, 356 + ... + 4466.

It is an arithmetic number, because the mean of its divisors is an integer number (2479536).

Almost surely, 2^9911621 is an apocalyptic number.

It is an amenable number.

9911621 is a deficient number, since it is larger than the sum of its proper divisors (6523).

9911621 is a wasteful number, since it uses less digits than its factorization.

9911621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6522.

The product of its digits is 972, while the sum is 29.

The square root of 9911621 is about 3148.2727010219. The cubic root of 9911621 is about 214.8069007166.

The spelling of 9911621 in words is "nine million, nine hundred eleven thousand, six hundred twenty-one".