9123428991 has 16 divisors (see below), whose sum is σ = 12634035200. Its totient is φ = 5849962560.

The previous prime is 9123428989. The next prime is 9123428999. The reversal of 9123428991 is 1998243219.

It is not a de Polignac number, because 9123428991 - 2¹ = 9123428989 is a prime.

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 9123428991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9123428999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 285766 + ... + 316083.

It is an arithmetic number, because the mean of its divisors is an integer number (789627200).

Almost surely, 2^9123428991 is an apocalyptic number.

9123428991 is a deficient number, since it is larger than the sum of its proper divisors (3510606209).

9123428991 is a wasteful number, since it uses less digits than its factorization.

9123428991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602046.

The product of its digits is 279936, while the sum is 48.

The square root of 9123428991 is about 95516.6424818209. The cubic root of 9123428991 is about 2089.5496683947.

The spelling of 9123428991 in words is "nine billion, one hundred twenty-three million, four hundred twenty-eight thousand, nine hundred ninety-one".