8991509405 has 4 divisors (see below), whose sum is σ = 10789811292. Its totient is φ = 7193207520.

The previous prime is 8991509399. The next prime is 8991509419. The reversal of 8991509405 is 5049051998.

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 5477628121 + 3513881284 = 74011^2 + 59278^2 .

It is not a de Polignac number, because 8991509405 - 2⁶ = 8991509341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 899150936 + ... + 899150945.

It is an arithmetic number, because the mean of its divisors is an integer number (2697452823).

Almost surely, 2^8991509405 is an apocalyptic number.

It is an amenable number.

8991509405 is a deficient number, since it is larger than the sum of its proper divisors (1798301887).

8991509405 is a wasteful number, since it uses less digits than its factorization.

8991509405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798301886.

The product of its (nonzero) digits is 583200, while the sum is 50.

The square root of 8991509405 is about 94823.5698811219. The cubic root of 8991509405 is about 2079.4295006052.

The spelling of 8991509405 in words is "eight billion, nine hundred ninety-one million, five hundred nine thousand, four hundred five".