16638936064 has 99 divisors (see below), whose sum is σ = 34697736957. Its totient is φ = 7974801408.

The previous prime is 16638936037. The next prime is 16638936071. The reversal of 16638936064 is 46063983661.

The square root of 16638936064 is 128992.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 8725054464 + 7913881600 = 93408^2 + 88960^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 119704507 + ... + 119704645.

Almost surely, 2^16638936064 is an apocalyptic number.

16638936064 is the 128992-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16638936064

16638936064 is an abundant number, since it is smaller than the sum of its proper divisors (18058800893).

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

16638936064 is an frugal number, since it uses more digits than its factorization.

16638936064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 52.

The spelling of 16638936064 in words is "sixteen billion, six hundred thirty-eight million, nine hundred thirty-six thousand, sixty-four".