72224309 has 2 divisors, whose sum is σ = 72224310. Its totient is φ = 72224308.

The previous prime is 72224303. The next prime is 72224311. The reversal of 72224309 is 90342227.

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., 59336209 + 12888100 = 7703^2 + 3590^2 .

It is a cyclic number.

It is not a de Polignac number, because 72224309 - 2⁴ = 72224293 is a prime.

Together with 72224311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72224303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36112154 + 36112155.

It is an arithmetic number, because the mean of its divisors is an integer number (36112155).

Almost surely, 2^72224309 is an apocalyptic number.

It is an amenable number.

72224309 is a deficient number, since it is larger than the sum of its proper divisors (1).

72224309 is an equidigital number, since it uses as much as digits as its factorization.

72224309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 72224309 is about 8498.4886303389. The cubic root of 72224309 is about 416.4483366746.

The spelling of 72224309 in words is "seventy-two million, two hundred twenty-four thousand, three hundred nine".