73251221 has 2 divisors, whose sum is σ = 73251222. Its totient is φ = 73251220.

The previous prime is 73251209. The next prime is 73251223. The reversal of 73251221 is 12215237.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72063121 + 1188100 = 8489^2 + 1090^2 .

It is an emirp because it is prime and its reverse (12215237) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73251221 - 2¹⁰ = 73250197 is a prime.

It is a Sophie Germain prime.

Together with 73251223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73251223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36625610 + 36625611.

It is an arithmetic number, because the mean of its divisors is an integer number (36625611).

Almost surely, 2^73251221 is an apocalyptic number.

It is an amenable number.

73251221 is a deficient number, since it is larger than the sum of its proper divisors (1).

73251221 is an equidigital number, since it uses as much as digits as its factorization.

73251221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 73251221 is about 8558.6927155962. The cubic root of 73251221 is about 418.4127943673.

Adding to 73251221 its reverse (12215237), we get a palindrome (85466458).

The spelling of 73251221 in words is "seventy-three million, two hundred fifty-one thousand, two hundred twenty-one".