73609658721 has 9 divisors (see below), whose sum is σ = 106326238291. Its totient is φ = 49072563192.

The previous prime is 73609658699. The next prime is 73609658753. The reversal of 73609658721 is 12785690637.

The square root of 73609658721 is 271311.

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

73609658721 is a `hidden beast` number, since 7 + 3 + 609 + 6 + 5 + 8 + 7 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13406166225 + 60203492496 = 115785^2 + 245364^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 73609658721 - 2⁷ = 73609658593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73609658821) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 768715 + ... + 859151.

Almost surely, 2^73609658721 is an apocalyptic number.

73609658721 is the 271311-st square number.

73609658721 is the 135656-th centered octagonal number.

It is an amenable number.

73609658721 is a deficient number, since it is larger than the sum of its proper divisors (32716579570).

73609658721 is an frugal number, since it uses more digits than its factorization.

73609658721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180880 (or 90440 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 73609658721 in words is "seventy-three billion, six hundred nine million, six hundred fifty-eight thousand, seven hundred twenty-one".