11121201521 has 2 divisors, whose sum is σ = 11121201522. Its totient is φ = 11121201520.

The previous prime is 11121201517. The next prime is 11121201529. The reversal of 11121201521 is 12510212111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6400000000 + 4721201521 = 80000^2 + 68711^2 .

It is a cyclic number.

It is not a de Polignac number, because 11121201521 - 2² = 11121201517 is a prime.

It is a super-2 number, since 2×11121201521² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11121201521.

It is not a weakly prime, because it can be changed into another prime (11121201529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5560600760 + 5560600761.

It is an arithmetic number, because the mean of its divisors is an integer number (5560600761).

Almost surely, 2^11121201521 is an apocalyptic number.

It is an amenable number.

11121201521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11121201521 is an equidigital number, since it uses as much as digits as its factorization.

11121201521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 17.

Adding to 11121201521 its reverse (12510212111), we get a palindrome (23631413632).

The spelling of 11121201521 in words is "eleven billion, one hundred twenty-one million, two hundred one thousand, five hundred twenty-one".