11521663649 has 2 divisors, whose sum is σ = 11521663650. Its totient is φ = 11521663648.

The previous prime is 11521663633. The next prime is 11521663709. The reversal of 11521663649 is 94636612511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10713285025 + 808378624 = 103505^2 + 28432^2 .

It is a cyclic number.

It is not a de Polignac number, because 11521663649 - 2⁴ = 11521663633 is a prime.

It is not a weakly prime, because it can be changed into another prime (11521663609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5760831824 + 5760831825.

It is an arithmetic number, because the mean of its divisors is an integer number (5760831825).

Almost surely, 2^11521663649 is an apocalyptic number.

It is an amenable number.

11521663649 is a deficient number, since it is larger than the sum of its proper divisors (1).

11521663649 is an equidigital number, since it uses as much as digits as its factorization.

11521663649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 44.

The spelling of 11521663649 in words is "eleven billion, five hundred twenty-one million, six hundred sixty-three thousand, six hundred forty-nine".