18978104577 has 4 divisors (see below), whose sum is σ = 25304139440. Its totient is φ = 12652069716.

The previous prime is 18978104531. The next prime is 18978104591. The reversal of 18978104577 is 77540187981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18978104577 - 2¹¹ = 18978102529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18978104597) 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, 3163017427 + ... + 3163017432.

It is an arithmetic number, because the mean of its divisors is an integer number (6326034860).

Almost surely, 2^18978104577 is an apocalyptic number.

It is an amenable number.

18978104577 is a deficient number, since it is larger than the sum of its proper divisors (6326034863).

18978104577 is an equidigital number, since it uses as much as digits as its factorization.

18978104577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6326034862.

The product of its (nonzero) digits is 3951360, while the sum is 57.

The spelling of 18978104577 in words is "eighteen billion, nine hundred seventy-eight million, one hundred four thousand, five hundred seventy-seven".