16611006601561 has 4 divisors (see below), whose sum is σ = 17146845524224. Its totient is φ = 16075167678900.

The previous prime is 16611006601529. The next prime is 16611006601577. The reversal of 16611006601561 is 16510660011661.

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 16611006601561 - 2⁵ = 16611006601529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16611006601361) 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, 267919461285 + ... + 267919461346.

It is an arithmetic number, because the mean of its divisors is an integer number (4286711381056).

Almost surely, 2^{16611006601561} is an apocalyptic number.

It is an amenable number.

16611006601561 is a deficient number, since it is larger than the sum of its proper divisors (535838922663).

16611006601561 is an equidigital number, since it uses as much as digits as its factorization.

16611006601561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535838922662.

The product of its (nonzero) digits is 38880, while the sum is 40.

The spelling of 16611006601561 in words is "sixteen trillion, six hundred eleven billion, six million, six hundred one thousand, five hundred sixty-one".