11751221 has 2 divisors, whose sum is σ = 11751222. Its totient is φ = 11751220.

The previous prime is 11751217. The next prime is 11751227. The reversal of 11751221 is 12215711.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11464996 + 286225 = 3386^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 11751221 - 2² = 11751217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11751193 and 11751202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11751227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5875610 + 5875611.

It is an arithmetic number, because the mean of its divisors is an integer number (5875611).

Almost surely, 2^11751221 is an apocalyptic number.

It is an amenable number.

11751221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11751221 is an equidigital number, since it uses as much as digits as its factorization.

11751221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 140, while the sum is 20.

The square root of 11751221 is about 3428.0053967285. The cubic root of 11751221 is about 227.3496716490.

Adding to 11751221 its reverse (12215711), we get a palindrome (23966932).

The spelling of 11751221 in words is "eleven million, seven hundred fifty-one thousand, two hundred twenty-one".