13656665412 has 72 divisors (see below), whose sum is σ = 37276623384. Its totient is φ = 4190731776.

The previous prime is 13656665387. The next prime is 13656665423. The reversal of 13656665412 is 21456665631.

It can be written as a sum of positive squares in 4 ways, for example, as 196953156 + 13459712256 = 14034^2 + 116016^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135448 + ... + 213680.

Almost surely, 2^13656665412 is an apocalyptic number.

13656665412 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13656665412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18638311692).

13656665412 is an abundant number, since it is smaller than the sum of its proper divisors (23619957972).

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

13656665412 is a wasteful number, since it uses less digits than its factorization.

13656665412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78629 (or 78624 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The spelling of 13656665412 in words is "thirteen billion, six hundred fifty-six million, six hundred sixty-five thousand, four hundred twelve".