163978553 has 4 divisors (see below), whose sum is σ = 166666788. Its totient is φ = 161290320.

The previous prime is 163978543. The next prime is 163978567. The reversal of 163978553 is 355879361.

163978553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35904064 + 128074489 = 5992^2 + 11317^2 .

It is a cyclic number.

It is not a de Polignac number, because 163978553 - 2⁴ = 163978537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 163978498 and 163978507.

It is not an unprimeable number, because it can be changed into a prime (163978543) 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, 1344026 + ... + 1344147.

It is an arithmetic number, because the mean of its divisors is an integer number (41666697).

Almost surely, 2^163978553 is an apocalyptic number.

It is an amenable number.

163978553 is a deficient number, since it is larger than the sum of its proper divisors (2688235).

163978553 is an equidigital number, since it uses as much as digits as its factorization.

163978553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2688234.

The product of its digits is 680400, while the sum is 47.

The square root of 163978553 is about 12805.4110828196. The cubic root of 163978553 is about 547.3465057643.

The spelling of 163978553 in words is "one hundred sixty-three million, nine hundred seventy-eight thousand, five hundred fifty-three".