16643708478564 has 144 divisors (see below), whose sum is σ = 40699696477440. Its totient is φ = 5293313847360.

The previous prime is 16643708478517. The next prime is 16643708478569. The reversal of 16643708478564 is 46587480734661.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is not an unprimeable number, because it can be changed into a prime (16643708478569) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7810279779 + ... + 7810281909.

Almost surely, 2^{16643708478564} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16643708478564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20349848238720).

16643708478564 is an abundant number, since it is smaller than the sum of its proper divisors (24055987998876).

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

16643708478564 is a wasteful number, since it uses less digits than its factorization.

16643708478564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4710 (or 4685 counting only the distinct ones).

The product of its (nonzero) digits is 650280960, while the sum is 69.

The spelling of 16643708478564 in words is "sixteen trillion, six hundred forty-three billion, seven hundred eight million, four hundred seventy-eight thousand, five hundred sixty-four".