16643564 has 48 divisors (see below), whose sum is σ = 34944000. Its totient is φ = 6785856.

The previous prime is 16643533. The next prime is 16643567. The reversal of 16643564 is 46534661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16643567) 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, 83537 + ... + 83735.

It is an arithmetic number, because the mean of its divisors is an integer number (728000).

Almost surely, 2^16643564 is an apocalyptic number.

16643564 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16643564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17472000).

16643564 is an abundant number, since it is smaller than the sum of its proper divisors (18300436).

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

16643564 is a wasteful number, since it uses less digits than its factorization.

16643564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 340 counting only the distinct ones).

The product of its digits is 51840, while the sum is 35.

The square root of 16643564 is about 4079.6524361764. The cubic root of 16643564 is about 255.3183976126.

The spelling of 16643564 in words is "sixteen million, six hundred forty-three thousand, five hundred sixty-four".