1281221 has 2 divisors, whose sum is σ = 1281222. Its totient is φ = 1281220.

The previous prime is 1281211. The next prime is 1281229. The reversal of 1281221 is 1221821.

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., 1020100 + 261121 = 1010^2 + 511^2 .

It is an emirp because it is prime and its reverse (1221821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281221 - 2⁶ = 1281157 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1281221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1281229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640610 + 640611.

It is an arithmetic number, because the mean of its divisors is an integer number (640611).

2^1281221 is an apocalyptic number.

It is an amenable number.

1281221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281221 is an equidigital number, since it uses as much as digits as its factorization.

1281221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 17.

The square root of 1281221 is about 1131.9103321377. The cubic root of 1281221 is about 108.6112176911.

The spelling of 1281221 in words is "one million, two hundred eighty-one thousand, two hundred twenty-one".