67381664 has 60 divisors (see below), whose sum is σ = 154934514. Its totient is φ = 28844928.

The previous prime is 67381663. The next prime is 67381667. The reversal of 67381664 is 46618376.

It can be written as a sum of positive squares in only one way, i.e., 47059600 + 20322064 = 6860^2 + 4508^2 .

It is not an unprimeable number, because it can be changed into a prime (67381663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 76394 + ... + 77270.

Almost surely, 2^67381664 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 67381664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77467257).

67381664 is an abundant number, since it is smaller than the sum of its proper divisors (87552850).

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

67381664 is an frugal number, since it uses more digits than its factorization.

67381664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915 (or 886 counting only the distinct ones).

The product of its digits is 145152, while the sum is 41.

The square root of 67381664 is about 8208.6335038178. The cubic root of 67381664 is about 406.9245675150.

The spelling of 67381664 in words is "sixty-seven million, three hundred eighty-one thousand, six hundred sixty-four".