73409321 has 2 divisors, whose sum is σ = 73409322. Its totient is φ = 73409320.

The previous prime is 73409257. The next prime is 73409327. The reversal of 73409321 is 12390437.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60528400 + 12880921 = 7780^2 + 3589^2 .

It is an emirp because it is prime and its reverse (12390437) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73409321 - 2⁶ = 73409257 is a prime.

It is not a weakly prime, because it can be changed into another prime (73409327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36704660 + 36704661.

It is an arithmetic number, because the mean of its divisors is an integer number (36704661).

Almost surely, 2^73409321 is an apocalyptic number.

It is an amenable number.

73409321 is a deficient number, since it is larger than the sum of its proper divisors (1).

73409321 is an equidigital number, since it uses as much as digits as its factorization.

73409321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 73409321 is about 8567.9239609138. The cubic root of 73409321 is about 418.7136017669.

Adding to 73409321 its reverse (12390437), we get a palindrome (85799758).

It can be divided in two parts, 7340 and 9321, that added together give a palindrome (16661).

The spelling of 73409321 in words is "seventy-three million, four hundred nine thousand, three hundred twenty-one".