11551638569 has 2 divisors, whose sum is σ = 11551638570. Its totient is φ = 11551638568.

The previous prime is 11551638541. The next prime is 11551638583. The reversal of 11551638569 is 96583615511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9173808400 + 2377830169 = 95780^2 + 48763^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11551638569 is a prime.

It is a super-2 number, since 2×11551638569² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11551634569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5775819284 + 5775819285.

It is an arithmetic number, because the mean of its divisors is an integer number (5775819285).

Almost surely, 2^11551638569 is an apocalyptic number.

It is an amenable number.

11551638569 is a deficient number, since it is larger than the sum of its proper divisors (1).

11551638569 is an equidigital number, since it uses as much as digits as its factorization.

11551638569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972000, while the sum is 50.

The spelling of 11551638569 in words is "eleven billion, five hundred fifty-one million, six hundred thirty-eight thousand, five hundred sixty-nine".