67861530071721 has 81 divisors (see below), whose sum is σ = 105946155498807. Its totient is φ = 41850715979520.

The previous prime is 67861530071669. The next prime is 67861530071747. The reversal of 67861530071721 is 12717003516876.

The square root of 67861530071721 is 8237811.

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

67861530071721 is a `hidden beast` number, since 6 + 7 + 8 + 615 + 3 + 0 + 0 + 7 + 17 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 50906241489321 + 16955288582400 = 7134861^2 + 4117680^2 .

It is not a de Polignac number, because 67861530071721 - 2³⁷ = 67724091118249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67861530073721) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 20190873081 + ... + 20190876441.

Almost surely, 2^{67861530071721} is an apocalyptic number.

67861530071721 is the 8237811-st square number.

67861530071721 is the 4118906-th centered octagonal number.

It is an amenable number.

67861530071721 is a deficient number, since it is larger than the sum of its proper divisors (38084625427086).

67861530071721 is an frugal number, since it uses more digits than its factorization.

67861530071721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6852 (or 3426 counting only the distinct ones).

The product of its (nonzero) digits is 2963520, while the sum is 54.

The spelling of 67861530071721 in words is "sixty-seven trillion, eight hundred sixty-one billion, five hundred thirty million, seventy-one thousand, seven hundred twenty-one".