71220217 has 2 divisors, whose sum is σ = 71220218. Its totient is φ = 71220216.

The previous prime is 71220209. The next prime is 71220223. The reversal of 71220217 is 71202217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58660281 + 12559936 = 7659^2 + 3544^2 .

It is a cyclic number.

It is not a de Polignac number, because 71220217 - 2³ = 71220209 is a prime.

It is not a weakly prime, because it can be changed into another prime (71221217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35610108 + 35610109.

It is an arithmetic number, because the mean of its divisors is an integer number (35610109).

Almost surely, 2^71220217 is an apocalyptic number.

It is an amenable number.

71220217 is a deficient number, since it is larger than the sum of its proper divisors (1).

71220217 is an equidigital number, since it uses as much as digits as its factorization.

71220217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 71220217 is about 8439.2071310047. The cubic root of 71220217 is about 414.5094450400.

The spelling of 71220217 in words is "seventy-one million, two hundred twenty thousand, two hundred seventeen".