72207217 has 2 divisors, whose sum is σ = 72207218. Its totient is φ = 72207216.

The previous prime is 72207203. The next prime is 72207229. The reversal of 72207217 is 71270227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67502656 + 4704561 = 8216^2 + 2169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72207217 is a prime.

It is not a weakly prime, because it can be changed into another prime (72207257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36103608 + 36103609.

It is an arithmetic number, because the mean of its divisors is an integer number (36103609).

Almost surely, 2^72207217 is an apocalyptic number.

It is an amenable number.

72207217 is a deficient number, since it is larger than the sum of its proper divisors (1).

72207217 is an equidigital number, since it uses as much as digits as its factorization.

72207217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 72207217 is about 8497.4829802713. The cubic root of 72207217 is about 416.4154830245.

The spelling of 72207217 in words is "seventy-two million, two hundred seven thousand, two hundred seventeen".