999173009680 has 40 divisors (see below), whose sum is σ = 2323586763072. Its totient is φ = 399581545344.

The previous prime is 999173009621. The next prime is 999173009689. The reversal of 999173009680 is 86900371999.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (61) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (999173009689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1002022 + ... + 1732741.

Almost surely, 2^999173009680 is an apocalyptic number.

It is an amenable number.

999173009680 is an abundant number, since it is smaller than the sum of its proper divisors (1324413753392).

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

999173009680 is a wasteful number, since it uses less digits than its factorization.

999173009680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739343 (or 2739337 counting only the distinct ones).

The product of its (nonzero) digits is 6613488, while the sum is 61.

The spelling of 999173009680 in words is "nine hundred ninety-nine billion, one hundred seventy-three million, nine thousand, six hundred eighty".