11215251521 has 2 divisors, whose sum is σ = 11215251522. Its totient is φ = 11215251520.

The previous prime is 11215251497. The next prime is 11215251533. The reversal of 11215251521 is 12515251211.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9783385921 + 1431865600 = 98911^2 + 37840^2 .

It is a cyclic number.

It is not a de Polignac number, because 11215251521 - 2⁶ = 11215251457 is a prime.

It is not a weakly prime, because it can be changed into another prime (11215251571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5607625760 + 5607625761.

It is an arithmetic number, because the mean of its divisors is an integer number (5607625761).

Almost surely, 2^11215251521 is an apocalyptic number.

It is an amenable number.

11215251521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11215251521 is an equidigital number, since it uses as much as digits as its factorization.

11215251521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1000, while the sum is 26.

The spelling of 11215251521 in words is "eleven billion, two hundred fifteen million, two hundred fifty-one thousand, five hundred twenty-one".