67721568 has 48 divisors (see below), whose sum is σ = 185504256. Its totient is φ = 21591680.

The previous prime is 67721551. The next prime is 67721569. The reversal of 67721568 is 86512776.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67721569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13128 + ... + 17543.

It is an arithmetic number, because the mean of its divisors is an integer number (3864672).

Almost surely, 2^67721568 is an apocalyptic number.

It is an amenable number.

67721568 is an abundant number, since it is smaller than the sum of its proper divisors (117782688).

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

67721568 is a wasteful number, since it uses less digits than its factorization.

67721568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30707 (or 30699 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The square root of 67721568 is about 8229.3115143370. The cubic root of 67721568 is about 407.6076582074.

The spelling of 67721568 in words is "sixty-seven million, seven hundred twenty-one thousand, five hundred sixty-eight".