13020816978 has 24 divisors (see below), whose sum is σ = 30381906828. Its totient is φ = 4006405152.

The previous prime is 13020816931. The next prime is 13020817013. The reversal of 13020816978 is 87961802031.

It can be written as a sum of positive squares in 2 ways, for example, as 12777363369 + 243453609 = 113037^2 + 15603^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27822025 + ... + 27822492.

Almost surely, 2^13020816978 is an apocalyptic number.

13020816978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

13020816978 is an abundant number, since it is smaller than the sum of its proper divisors (17361089850).

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

13020816978 is a wasteful number, since it uses less digits than its factorization.

13020816978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55644538 (or 55644535 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 13020816978 in words is "thirteen billion, twenty million, eight hundred sixteen thousand, nine hundred seventy-eight".