11721560161 has 16 divisors (see below), whose sum is σ = 12496176000. Its totient is φ = 10963617408.

The previous prime is 11721560119. The next prime is 11721560171. The reversal of 11721560161 is 16106512711.

It is a cyclic number.

It is not a de Polignac number, because 11721560161 - 2⁹ = 11721559649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11721560101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 460381 + ... + 485173.

It is an arithmetic number, because the mean of its divisors is an integer number (781011000).

Almost surely, 2^11721560161 is an apocalyptic number.

It is an amenable number.

11721560161 is a deficient number, since it is larger than the sum of its proper divisors (774615839).

11721560161 is a wasteful number, since it uses less digits than its factorization.

11721560161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25128.

The product of its (nonzero) digits is 2520, while the sum is 31.

The spelling of 11721560161 in words is "eleven billion, seven hundred twenty-one million, five hundred sixty thousand, one hundred sixty-one".