16478921689 has 4 divisors (see below), whose sum is σ = 17010499840. Its totient is φ = 15947343540.

The previous prime is 16478921687. The next prime is 16478921699. The reversal of 16478921689 is 98612987461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16478921689 - 2¹ = 16478921687 is a prime.

It is a super-2 number, since 2×16478921689² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16478921681) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 265789029 + ... + 265789090.

It is an arithmetic number, because the mean of its divisors is an integer number (4252624960).

Almost surely, 2^16478921689 is an apocalyptic number.

It is an amenable number.

16478921689 is a deficient number, since it is larger than the sum of its proper divisors (531578151).

16478921689 is an equidigital number, since it uses as much as digits as its factorization.

16478921689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531578150.

The product of its digits is 10450944, while the sum is 61.

The spelling of 16478921689 in words is "sixteen billion, four hundred seventy-eight million, nine hundred twenty-one thousand, six hundred eighty-nine".