7215217 has 2 divisors, whose sum is σ = 7215218. Its totient is φ = 7215216.

The previous prime is 7215209. The next prime is 7215223. The reversal of 7215217 is 7125127.

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., 3825936 + 3389281 = 1956^2 + 1841^2 .

It is a cyclic number.

It is not a de Polignac number, because 7215217 - 2³ = 7215209 is a prime.

It is an Ulam number.

It is equal to p₄₉₀₂₈₂ and since 7215217 and 490282 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 7215191 and 7215200.

It is not a weakly prime, because it can be changed into another prime (7215227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3607608 + 3607609.

It is an arithmetic number, because the mean of its divisors is an integer number (3607609).

Almost surely, 2^7215217 is an apocalyptic number.

It is an amenable number.

7215217 is a deficient number, since it is larger than the sum of its proper divisors (1).

7215217 is an equidigital number, since it uses as much as digits as its factorization.

7215217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 980, while the sum is 25.

The square root of 7215217 is about 2686.1155969169. The cubic root of 7215217 is about 193.2338168640.

The spelling of 7215217 in words is "seven million, two hundred fifteen thousand, two hundred seventeen".