16538791689 has 36 divisors (see below), whose sum is σ = 27921532080. Its totient is φ = 9405894960.

The previous prime is 16538791667. The next prime is 16538791691. The reversal of 16538791689 is 98619783561.

16538791689 is a `hidden beast` number, since 1 + 6 + 538 + 7 + 9 + 16 + 89 = 666.

It is not a de Polignac number, because 16538791689 - 2¹³ = 16538783497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (16538791189) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4182 + ... + 181920.

Almost surely, 2^16538791689 is an apocalyptic number.

It is an amenable number.

16538791689 is a deficient number, since it is larger than the sum of its proper divisors (11382740391).

16538791689 is a wasteful number, since it uses less digits than its factorization.

16538791689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177970 (or 177960 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 63.

The spelling of 16538791689 in words is "sixteen billion, five hundred thirty-eight million, seven hundred ninety-one thousand, six hundred eighty-nine".