72820213 has 2 divisors, whose sum is σ = 72820214. Its totient is φ = 72820212.

The previous prime is 72820207. The next prime is 72820259. The reversal of 72820213 is 31202827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70442449 + 2377764 = 8393^2 + 1542^2 .

It is an emirp because it is prime and its reverse (31202827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72820213 - 2⁹ = 72819701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72820283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36410106 + 36410107.

It is an arithmetic number, because the mean of its divisors is an integer number (36410107).

Almost surely, 2^72820213 is an apocalyptic number.

It is an amenable number.

72820213 is a deficient number, since it is larger than the sum of its proper divisors (1).

72820213 is an equidigital number, since it uses as much as digits as its factorization.

72820213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 72820213 is about 8533.4760209425. The cubic root of 72820213 is about 417.5905367376.

The spelling of 72820213 in words is "seventy-two million, eight hundred twenty thousand, two hundred thirteen".