73563443706521 has 4 divisors (see below), whose sum is σ = 74321829724212. Its totient is φ = 72805057688832.

The previous prime is 73563443706469. The next prime is 73563443706553. The reversal of 73563443706521 is 12560734436537.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53749719216400 + 19813724490121 = 7331420^2 + 4451261^2 .

It is a cyclic number.

It is not a de Polignac number, because 73563443706521 - 2⁴⁶ = 3194699528857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (73563440706521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 379193008700 + ... + 379193008893.

It is an arithmetic number, because the mean of its divisors is an integer number (18580457431053).

Almost surely, 2^{73563443706521} is an apocalyptic number.

It is an amenable number.

73563443706521 is a deficient number, since it is larger than the sum of its proper divisors (758386017691).

73563443706521 is an equidigital number, since it uses as much as digits as its factorization.

73563443706521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758386017690.

The product of its (nonzero) digits is 38102400, while the sum is 56.

The spelling of 73563443706521 in words is "seventy-three trillion, five hundred sixty-three billion, four hundred forty-three million, seven hundred six thousand, five hundred twenty-one".