67112601721 has 15 divisors (see below), whose sum is σ = 73857900415. Its totient is φ = 60982959400.

The previous prime is 67112601719. The next prime is 67112601779. The reversal of 67112601721 is 12710621176.

The square root of 67112601721 is 259061.

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., 64014566121 + 3098035600 = 253011^2 + 55660^2 .

It is not a de Polignac number, because 67112601721 - 2¹ = 67112601719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67112601701) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 31345311 + ... + 31347451.

Almost surely, 2^67112601721 is an apocalyptic number.

67112601721 is the 259061-st square number.

67112601721 is the 129531-st centered octagonal number.

It is an amenable number.

67112601721 is a deficient number, since it is larger than the sum of its proper divisors (6745298694).

67112601721 is an frugal number, since it uses more digits than its factorization.

67112601721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4326 (or 2152 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 34.

Multiplying 67112601721 by its product of nonzero digits (7056), we get a square (473546517743376 = 21761124²).

The spelling of 67112601721 in words is "sixty-seven billion, one hundred twelve million, six hundred one thousand, seven hundred twenty-one".