13520549978 has 16 divisors (see below), whose sum is σ = 21853172040. Its totient is φ = 6236744256.

The previous prime is 13520549971. The next prime is 13520549993. The reversal of 13520549978 is 87994502531.

13520549978 is digitally balanced in base 2, 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 4 ways, for example, as 13011280489 + 509269489 = 114067^2 + 22567^2 .

It is not an unprimeable number, because it can be changed into a prime (13520549971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98825 + ... + 191852.

Almost surely, 2^13520549978 is an apocalyptic number.

13520549978 is a deficient number, since it is larger than the sum of its proper divisors (8332622062).

13520549978 is a wasteful number, since it uses less digits than its factorization.

13520549978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292481.

The product of its (nonzero) digits is 2721600, while the sum is 53.

The spelling of 13520549978 in words is "thirteen billion, five hundred twenty million, five hundred forty-nine thousand, nine hundred seventy-eight".