73681609 has 2 divisors, whose sum is σ = 73681610. Its totient is φ = 73681608.

The previous prime is 73681603. The next prime is 73681649. The reversal of 73681609 is 90618637.

It is an a-pointer prime, because the next prime (73681649) can be obtained adding 73681609 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68112009 + 5569600 = 8253^2 + 2360^2 .

It is a cyclic number.

It is not a de Polignac number, because 73681609 - 2⁷ = 73681481 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (73681603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36840804 + 36840805.

It is an arithmetic number, because the mean of its divisors is an integer number (36840805).

Almost surely, 2^73681609 is an apocalyptic number.

It is an amenable number.

73681609 is a deficient number, since it is larger than the sum of its proper divisors (1).

73681609 is an equidigital number, since it uses as much as digits as its factorization.

73681609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 73681609 is about 8583.7992171299. The cubic root of 73681609 is about 419.2306569834.

The spelling of 73681609 in words is "seventy-three million, six hundred eighty-one thousand, six hundred nine".