13506479978 has 8 divisors (see below), whose sum is σ = 20487357540. Its totient is φ = 6677360800.

The previous prime is 13506479971. The next prime is 13506479983. The reversal of 13506479978 is 87997460531.

13506479978 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 9733203649 + 3773276329 = 98657^2 + 61427^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×13506479978² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13506479971) 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, 37939373 + ... + 37939728.

Almost surely, 2^13506479978 is an apocalyptic number.

13506479978 is a deficient number, since it is larger than the sum of its proper divisors (6980877562).

13506479978 is an equidigital number, since it uses as much as digits as its factorization.

13506479978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75879192.

The product of its (nonzero) digits is 11430720, while the sum is 59.

The spelling of 13506479978 in words is "thirteen billion, five hundred six million, four hundred seventy-nine thousand, nine hundred seventy-eight".