188921664 has 84 divisors (see below), whose sum is σ = 549049956. Its totient is φ = 62097408.

The previous prime is 188921647. The next prime is 188921669. The reversal of 188921664 is 466129881.

It can be written as a sum of positive squares in 2 ways, for example, as 161798400 + 27123264 = 12720^2 + 5208^2 .

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (188921669) 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, 39802 + ... + 44294.

It is an arithmetic number, because the mean of its divisors is an integer number (6536309).

Almost surely, 2^188921664 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 188921664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274524978).

188921664 is an abundant number, since it is smaller than the sum of its proper divisors (360128292).

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

188921664 is a wasteful number, since it uses less digits than its factorization.

188921664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4584 (or 4571 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 188921664 is about 13744.8777368153. The cubic root of 188921664 is about 573.8000574322.

The spelling of 188921664 in words is "one hundred eighty-eight million, nine hundred twenty-one thousand, six hundred sixty-four".