11515220251 has 2 divisors, whose sum is σ = 11515220252. Its totient is φ = 11515220250.

The previous prime is 11515220221. The next prime is 11515220261. The reversal of 11515220251 is 15202251511.

It is a happy number.

11515220251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11515220251 - 2²¹ = 11513123099 is a prime.

It is not a weakly prime, because it can be changed into another prime (11515220221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5757610125 + 5757610126.

It is an arithmetic number, because the mean of its divisors is an integer number (5757610126).

Almost surely, 2^11515220251 is an apocalyptic number.

11515220251 is a deficient number, since it is larger than the sum of its proper divisors (1).

11515220251 is an equidigital number, since it uses as much as digits as its factorization.

11515220251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1000, while the sum is 25.

Adding to 11515220251 its reverse (15202251511), we get a palindrome (26717471762).

The spelling of 11515220251 in words is "eleven billion, five hundred fifteen million, two hundred twenty thousand, two hundred fifty-one".