16549494561 has 8 divisors (see below), whose sum is σ = 24517769760. Its totient is φ = 11032996356.

The previous prime is 16549494541. The next prime is 16549494593.

16549494561 is a `hidden beast` number, since 1 + 6 + 5 + 494 + 94 + 5 + 61 = 666.

16549494561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 16549494561 - 2⁷ = 16549494433 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 16549494498 and 16549494507.

It is not an unprimeable number, because it can be changed into a prime (16549494541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306472095 + ... + 306472148.

It is an arithmetic number, because the mean of its divisors is an integer number (3064721220).

Almost surely, 2^16549494561 is an apocalyptic number.

It is an amenable number.

16549494561 is a deficient number, since it is larger than the sum of its proper divisors (7968275199).

16549494561 is an equidigital number, since it uses as much as digits as its factorization.

16549494561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612944252 (or 612944246 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 54.

The spelling of 16549494561 in words is "sixteen billion, five hundred forty-nine million, four hundred ninety-four thousand, five hundred sixty-one".