16543981656 has 48 divisors (see below), whose sum is σ = 45019011960. Its totient is φ = 5488519680.

The previous prime is 16543981651. The next prime is 16543981667. The reversal of 16543981656 is 65618934561.

16543981656 is a `hidden beast` number, since 1 + 6 + 543 + 98 + 1 + 6 + 5 + 6 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16543981651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 529305 + ... + 559688.

Almost surely, 2^16543981656 is an apocalyptic number.

It is an amenable number.

16543981656 is an abundant number, since it is smaller than the sum of its proper divisors (28475030304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16543981656 is a wasteful number, since it uses less digits than its factorization.

16543981656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089216 (or 1089209 counting only the distinct ones).

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

The spelling of 16543981656 in words is "sixteen billion, five hundred forty-three million, nine hundred eighty-one thousand, six hundred fifty-six".