72000221 has 2 divisors, whose sum is σ = 72000222. Its totient is φ = 72000220.

The previous prime is 72000217. The next prime is 72000239. The reversal of 72000221 is 12200027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56040196 + 15960025 = 7486^2 + 3995^2 .

It is a cyclic number.

It is not a de Polignac number, because 72000221 - 2² = 72000217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72000196 and 72000205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72000241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36000110 + 36000111.

It is an arithmetic number, because the mean of its divisors is an integer number (36000111).

Almost surely, 2^72000221 is an apocalyptic number.

It is an amenable number.

72000221 is a deficient number, since it is larger than the sum of its proper divisors (1).

72000221 is an equidigital number, since it uses as much as digits as its factorization.

72000221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 72000221 is about 8485.2943967785. The cubic root of 72000221 is about 416.0171902567.

Adding to 72000221 its reverse (12200027), we get a palindrome (84200248).

The spelling of 72000221 in words is "seventy-two million, two hundred twenty-one", and thus it is an aban number.