16563453993 has 16 divisors (see below), whose sum is σ = 24541648000. Its totient is φ = 11040863760.

The previous prime is 16563453971. The next prime is 16563453997. The reversal of 16563453993 is 39935436561.

16563453993 is a `hidden beast` number, since 1 + 6 + 563 + 45 + 39 + 9 + 3 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-16563453993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16563453997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196503 + ... + 267843.

It is an arithmetic number, because the mean of its divisors is an integer number (1533853000).

Almost surely, 2^16563453993 is an apocalyptic number.

It is an amenable number.

16563453993 is a deficient number, since it is larger than the sum of its proper divisors (7978194007).

16563453993 is an equidigital number, since it uses as much as digits as its factorization.

16563453993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79949 (or 79943 counting only the distinct ones).

The product of its digits is 7873200, while the sum is 54.

The spelling of 16563453993 in words is "sixteen billion, five hundred sixty-three million, four hundred fifty-three thousand, nine hundred ninety-three".