11721511069 has 4 divisors (see below), whose sum is σ = 11730049596. Its totient is φ = 11712972544.

The previous prime is 11721511013. The next prime is 11721511097. The reversal of 11721511069 is 96011512711.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11074826169 + 646684900 = 105237^2 + 25430^2 .

It is a cyclic number.

It is not a de Polignac number, because 11721511069 - 2²¹ = 11719413917 is a prime.

It is a super-2 number, since 2×11721511069² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11721521069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4267204 + ... + 4269949.

It is an arithmetic number, because the mean of its divisors is an integer number (2932512399).

Almost surely, 2^11721511069 is an apocalyptic number.

It is an amenable number.

11721511069 is a deficient number, since it is larger than the sum of its proper divisors (8538527).

11721511069 is an equidigital number, since it uses as much as digits as its factorization.

11721511069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8538526.

The product of its (nonzero) digits is 3780, while the sum is 34.

The spelling of 11721511069 in words is "eleven billion, seven hundred twenty-one million, five hundred eleven thousand, sixty-nine".