7221281 has 2 divisors, whose sum is σ = 7221282. Its totient is φ = 7221280.

The previous prime is 7221259. The next prime is 7221283. The reversal of 7221281 is 1821227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4661281 + 2560000 = 2159^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 7221281 - 2²² = 3026977 is a prime.

It is a super-2 number, since 2×7221281² = 104293798561922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 7221283, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7221283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3610640 + 3610641.

It is an arithmetic number, because the mean of its divisors is an integer number (3610641).

Almost surely, 2^7221281 is an apocalyptic number.

It is an amenable number.

7221281 is a deficient number, since it is larger than the sum of its proper divisors (1).

7221281 is an equidigital number, since it uses as much as digits as its factorization.

7221281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 23.

The square root of 7221281 is about 2687.2441273543. The cubic root of 7221281 is about 193.2879358992.

The spelling of 7221281 in words is "seven million, two hundred twenty-one thousand, two hundred eighty-one".