7221649 has 2 divisors, whose sum is σ = 7221650. Its totient is φ = 7221648.

The previous prime is 7221631. The next prime is 7221661. The reversal of 7221649 is 9461227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4558225 + 2663424 = 2135^2 + 1632^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7221649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7221649.

It is not a weakly prime, because it can be changed into another prime (7221619) 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, 3610824 + 3610825.

It is an arithmetic number, because the mean of its divisors is an integer number (3610825).

Almost surely, 2^7221649 is an apocalyptic number.

It is an amenable number.

7221649 is a deficient number, since it is larger than the sum of its proper divisors (1).

7221649 is an equidigital number, since it uses as much as digits as its factorization.

7221649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 31.

The square root of 7221649 is about 2687.3125981173. The cubic root of 7221649 is about 193.2912191926.

The spelling of 7221649 in words is "seven million, two hundred twenty-one thousand, six hundred forty-nine".