16634625561 has 8 divisors (see below), whose sum is σ = 24643889760. Its totient is φ = 11089750356.

The previous prime is 16634625521. The next prime is 16634625569. The reversal of 16634625561 is 16552643661.

16634625561 is a `hidden beast` number, since 1 + 6 + 6 + 34 + 62 + 556 + 1 = 666.

It is not a de Polignac number, because 16634625561 - 2¹⁷ = 16634494489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16634625569) 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, 308048595 + ... + 308048648.

It is an arithmetic number, because the mean of its divisors is an integer number (3080486220).

Almost surely, 2^16634625561 is an apocalyptic number.

It is an amenable number.

16634625561 is a deficient number, since it is larger than the sum of its proper divisors (8009264199).

16634625561 is an equidigital number, since it uses as much as digits as its factorization.

16634625561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616097252 (or 616097246 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The spelling of 16634625561 in words is "sixteen billion, six hundred thirty-four million, six hundred twenty-five thousand, five hundred sixty-one".