13722611778 has 18 divisors (see below), whose sum is σ = 29733402387. Its totient is φ = 4574038260.

The previous prime is 13722611731. The next prime is 13722611797. The reversal of 13722611778 is 87711622731.

13722611778 is a `hidden beast` number, since 1 + 3 + 7 + 22 + 611 + 7 + 7 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6861305889 + 6861305889 = 82833^2 + 82833^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=82833.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 483193 + ... + 510803.

Almost surely, 2^13722611778 is an apocalyptic number.

13722611778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

13722611778 is an abundant number, since it is smaller than the sum of its proper divisors (16010790609).

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

13722611778 is an frugal number, since it uses more digits than its factorization.

13722611778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55230 (or 27616 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The spelling of 13722611778 in words is "thirteen billion, seven hundred twenty-two million, six hundred eleven thousand, seven hundred seventy-eight".