11959720321 has 4 divisors (see below), whose sum is σ = 12372124500. Its totient is φ = 11547316144.

The previous prime is 11959720319. The next prime is 11959720351. The reversal of 11959720321 is 12302795911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12302795911 = 7 ⋅1757542273.

It can be written as a sum of positive squares in 2 ways, for example, as 2312551921 + 9647168400 = 48089^2 + 98220^2 .

It is a cyclic number.

It is not a de Polignac number, because 11959720321 - 2¹ = 11959720319 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11959720351) 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, 206202046 + ... + 206202103.

It is an arithmetic number, because the mean of its divisors is an integer number (3093031125).

Almost surely, 2^11959720321 is an apocalyptic number.

It is an amenable number.

11959720321 is a deficient number, since it is larger than the sum of its proper divisors (412404179).

11959720321 is an equidigital number, since it uses as much as digits as its factorization.

11959720321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412404178.

The product of its (nonzero) digits is 34020, while the sum is 40.

The spelling of 11959720321 in words is "eleven billion, nine hundred fifty-nine million, seven hundred twenty thousand, three hundred twenty-one".