11551121 has 2 divisors, whose sum is σ = 11551122. Its totient is φ = 11551120.

The previous prime is 11551117. The next prime is 11551123. The reversal of 11551121 is 12115511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10627600 + 923521 = 3260^2 + 961^2 .

It is a cyclic number.

It is not a de Polignac number, because 11551121 - 2² = 11551117 is a prime.

Together with 11551123, it forms a pair of twin primes.

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 11551121.

It is not a weakly prime, because it can be changed into another prime (11551123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5775560 + 5775561.

It is an arithmetic number, because the mean of its divisors is an integer number (5775561).

Almost surely, 2^11551121 is an apocalyptic number.

It is an amenable number.

11551121 is a deficient number, since it is larger than the sum of its proper divisors (1).

11551121 is an equidigital number, since it uses as much as digits as its factorization.

11551121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50, while the sum is 17.

The square root of 11551121 is about 3398.6940138824. The cubic root of 11551121 is about 226.0518389451.

Adding to 11551121 its reverse (12115511), we get a palindrome (23666632).

The spelling of 11551121 in words is "eleven million, five hundred fifty-one thousand, one hundred twenty-one".