67216784644 has 9 divisors (see below), whose sum is σ = 117630280551. Its totient is φ = 33608133060.

The previous prime is 67216784639. The next prime is 67216784647. The reversal of 67216784644 is 44648761276.

The square root of 67216784644 is 259262.

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

It is a super-2 number, since 2×67216784644² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67216784647) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 453709 + ... + 583339.

Almost surely, 2^67216784644 is an apocalyptic number.

67216784644 is the 259262-nd square number.

It is an amenable number.

67216784644 is a deficient number, since it is larger than the sum of its proper divisors (50413495907).

67216784644 is an frugal number, since it uses more digits than its factorization.

67216784644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259266 (or 129633 counting only the distinct ones).

The product of its digits is 10838016, while the sum is 55.

The spelling of 67216784644 in words is "sixty-seven billion, two hundred sixteen million, seven hundred eighty-four thousand, six hundred forty-four".