12665923720 has 16 divisors (see below), whose sum is σ = 28498328460. Its totient is φ = 5066369472.

The previous prime is 12665923717. The next prime is 12665923723. The reversal of 12665923720 is 2732956621.

It is an interprime number because it is at equal distance from previous prime (12665923717) and next prime (12665923723).

It can be written as a sum of positive squares in 2 ways, for example, as 11911103044 + 754820676 = 109138^2 + 27474^2 .

It is not an unprimeable number, because it can be changed into a prime (12665923723) 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, 158324007 + ... + 158324086.

Almost surely, 2^12665923720 is an apocalyptic number.

12665923720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12665923720 is an abundant number, since it is smaller than the sum of its proper divisors (15832404740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12665923720 is a wasteful number, since it uses less digits than its factorization.

12665923720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316648104 (or 316648100 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 43.

The spelling of 12665923720 in words is "twelve billion, six hundred sixty-five million, nine hundred twenty-three thousand, seven hundred twenty".