12051720685 has 4 divisors (see below), whose sum is σ = 14462064828. Its totient is φ = 9641376544.

The previous prime is 12051720661. The next prime is 12051720749. The reversal of 12051720685 is 58602715021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58602715021 = 353 ⋅166013357.

It can be written as a sum of positive squares in 2 ways, for example, as 1767529764 + 10284190921 = 42042^2 + 101411^2 .

It is a cyclic number.

It is not a de Polignac number, because 12051720685 - 2⁹ = 12051720173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1205172064 + ... + 1205172073.

It is an arithmetic number, because the mean of its divisors is an integer number (3615516207).

Almost surely, 2^12051720685 is an apocalyptic number.

It is an amenable number.

12051720685 is a deficient number, since it is larger than the sum of its proper divisors (2410344143).

12051720685 is an equidigital number, since it uses as much as digits as its factorization.

12051720685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2410344142.

The product of its (nonzero) digits is 33600, while the sum is 37.

It can be divided in two parts, 12051 and 720685, that added together give a square (732736 = 856²).

The spelling of 12051720685 in words is "twelve billion, fifty-one million, seven hundred twenty thousand, six hundred eighty-five".