7216697221 has 2 divisors, whose sum is σ = 7216697222. Its totient is φ = 7216697220.

The previous prime is 7216697219. The next prime is 7216697273. The reversal of 7216697221 is 1227966127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6726296196 + 490401025 = 82014^2 + 22145^2 .

It is an emirp because it is prime and its reverse (1227966127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7216697221 - 2¹ = 7216697219 is a prime.

Together with 7216697219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7216667221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3608348610 + 3608348611.

It is an arithmetic number, because the mean of its divisors is an integer number (3608348611).

Almost surely, 2^7216697221 is an apocalyptic number.

It is an amenable number.

7216697221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7216697221 is an equidigital number, since it uses as much as digits as its factorization.

7216697221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 7216697221 is about 84951.1460840876. The cubic root of 7216697221 is about 1932.4703010464.

The spelling of 7216697221 in words is "seven billion, two hundred sixteen million, six hundred ninety-seven thousand, two hundred twenty-one".