17999578921 has 8 divisors (see below), whose sum is σ = 19014357600. Its totient is φ = 16991543520.

The previous prime is 17999578889. The next prime is 17999578939. The reversal of 17999578921 is 12987599971.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 17999578921 - 2⁵ = 17999578889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17999578321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1680331 + ... + 1691008.

It is an arithmetic number, because the mean of its divisors is an integer number (2376794700).

Almost surely, 2^17999578921 is an apocalyptic number.

It is an amenable number.

17999578921 is a deficient number, since it is larger than the sum of its proper divisors (1014778679).

17999578921 is a wasteful number, since it uses less digits than its factorization.

17999578921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3371639.

The product of its digits is 25719120, while the sum is 67.

The spelling of 17999578921 in words is "seventeen billion, nine hundred ninety-nine million, five hundred seventy-eight thousand, nine hundred twenty-one".