73636561 has 2 divisors, whose sum is σ = 73636562. Its totient is φ = 73636560.

The previous prime is 73636529. The next prime is 73636601. The reversal of 73636561 is 16563637.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48385936 + 25250625 = 6956^2 + 5025^2 .

It is an emirp because it is prime and its reverse (16563637) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73636561 - 2⁵ = 73636529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 73636561.

It is not a weakly prime, because it can be changed into another prime (73636361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36818280 + 36818281.

It is an arithmetic number, because the mean of its divisors is an integer number (36818281).

Almost surely, 2^73636561 is an apocalyptic number.

It is an amenable number.

73636561 is a deficient number, since it is larger than the sum of its proper divisors (1).

73636561 is an equidigital number, since it uses as much as digits as its factorization.

73636561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 37.

The square root of 73636561 is about 8581.1748030209. The cubic root of 73636561 is about 419.1452021326.

It can be divided in two parts, 7363 and 6561, that added together give a square (13924 = 118²).

The spelling of 73636561 in words is "seventy-three million, six hundred thirty-six thousand, five hundred sixty-one".