73643137564561 has 4 divisors (see below), whose sum is σ = 76182556101300. Its totient is φ = 71103719027824.

The previous prime is 73643137564541. The next prime is 73643137564627. The reversal of 73643137564561 is 16546573134637.

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 17153347555600 + 56489790008961 = 4141660^2 + 7515969^2 .

It is a cyclic number.

It is not a de Polignac number, because 73643137564561 - 2¹⁵ = 73643137531793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 73643137564561.

It is not an unprimeable number, because it can be changed into a prime (73643137564541) 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, 1269709268326 + ... + 1269709268383.

It is an arithmetic number, because the mean of its divisors is an integer number (19045639025325).

Almost surely, 2^{73643137564561} is an apocalyptic number.

It is an amenable number.

73643137564561 is a deficient number, since it is larger than the sum of its proper divisors (2539418536739).

73643137564561 is a wasteful number, since it uses less digits than its factorization.

73643137564561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2539418536738.

The product of its digits is 114307200, while the sum is 61.

The spelling of 73643137564561 in words is "seventy-three trillion, six hundred forty-three billion, one hundred thirty-seven million, five hundred sixty-four thousand, five hundred sixty-one".