8991421164 has 72 divisors (see below), whose sum is σ = 25594383360. Its totient is φ = 2636776800.

The previous prime is 8991421157. The next prime is 8991421177. The reversal of 8991421164 is 4611241998.

It is a happy number.

8991421164 is a `hidden beast` number, since 89 + 91 + 421 + 1 + 64 = 666.

It is a super-2 number, since 2×8991421164² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 353944 + ... + 378495.

Almost surely, 2^8991421164 is an apocalyptic number.

It is an amenable number.

8991421164 is an abundant number, since it is smaller than the sum of its proper divisors (16602962196).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8991421164 is a wasteful number, since it uses less digits than its factorization.

8991421164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732491 (or 732486 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 8991421164 is about 94823.1045895461. The cubic root of 8991421164 is about 2079.4226982049.

The spelling of 8991421164 in words is "eight billion, nine hundred ninety-one million, four hundred twenty-one thousand, one hundred sixty-four".