1288380221 has 2 divisors, whose sum is σ = 1288380222. Its totient is φ = 1288380220.

The previous prime is 1288380209. The next prime is 1288380251. The reversal of 1288380221 is 1220838821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1081423225 + 206956996 = 32885^2 + 14386^2 .

It is an emirp because it is prime and its reverse (1220838821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1288380221 - 2⁶ = 1288380157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1288380251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644190110 + 644190111.

It is an arithmetic number, because the mean of its divisors is an integer number (644190111).

Almost surely, 2^1288380221 is an apocalyptic number.

It is an amenable number.

1288380221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1288380221 is an equidigital number, since it uses as much as digits as its factorization.

1288380221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 1288380221 is about 35894.0137209535. The cubic root of 1288380221 is about 1088.1314171045.

The spelling of 1288380221 in words is "one billion, two hundred eighty-eight million, three hundred eighty thousand, two hundred twenty-one".