16605651081 has 4 divisors (see below), whose sum is σ = 22140868112. Its totient is φ = 11070434052.

The previous prime is 16605651059. The next prime is 16605651091. The reversal of 16605651081 is 18015650661.

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 not a de Polignac number, because 16605651081 - 2¹⁰ = 16605650057 is a prime.

It is a super-2 number, since 2×16605651081² (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 (16605651091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2767608511 + ... + 2767608516.

It is an arithmetic number, because the mean of its divisors is an integer number (5535217028).

Almost surely, 2^16605651081 is an apocalyptic number.

It is an amenable number.

16605651081 is a deficient number, since it is larger than the sum of its proper divisors (5535217031).

16605651081 is an equidigital number, since it uses as much as digits as its factorization.

16605651081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5535217030.

The product of its (nonzero) digits is 43200, while the sum is 39.

The spelling of 16605651081 in words is "sixteen billion, six hundred five million, six hundred fifty-one thousand, eighty-one".