18978968577 has 16 divisors (see below), whose sum is σ = 26643744000. Its totient is φ = 11983749264.

The previous prime is 18978968551. The next prime is 18978968647. The reversal of 18978968577 is 77586987981.

It is a happy number.

It is not a de Polignac number, because 18978968577 - 2⁶ = 18978968513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18978968499 and 18978968508.

It is not an unprimeable number, because it can be changed into a prime (18978968507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203674 + ... + 281852.

It is an arithmetic number, because the mean of its divisors is an integer number (1665234000).

Almost surely, 2^18978968577 is an apocalyptic number.

It is an amenable number.

18978968577 is a deficient number, since it is larger than the sum of its proper divisors (7664775423).

18978968577 is a wasteful number, since it uses less digits than its factorization.

18978968577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82460.

The product of its digits is 426746880, while the sum is 75.

The spelling of 18978968577 in words is "eighteen billion, nine hundred seventy-eight million, nine hundred sixty-eight thousand, five hundred seventy-seven".