11187857509 has 2 divisors, whose sum is σ = 11187857510. Its totient is φ = 11187857508.

The previous prime is 11187857507. The next prime is 11187857521. The reversal of 11187857509 is 90575878111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6007025025 + 5180832484 = 77505^2 + 71978^2 .

It is a cyclic number.

It is not a de Polignac number, because 11187857509 - 2¹ = 11187857507 is a prime.

Together with 11187857507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11187857507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5593928754 + 5593928755.

It is an arithmetic number, because the mean of its divisors is an integer number (5593928755).

Almost surely, 2^11187857509 is an apocalyptic number.

It is an amenable number.

11187857509 is a deficient number, since it is larger than the sum of its proper divisors (1).

11187857509 is an equidigital number, since it uses as much as digits as its factorization.

11187857509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 705600, while the sum is 52.

The spelling of 11187857509 in words is "eleven billion, one hundred eighty-seven million, eight hundred fifty-seven thousand, five hundred nine".