18921807578063 has 8 divisors (see below), whose sum is σ = 20377460810448. Its totient is φ = 17466172856064.

The previous prime is 18921807578029. The next prime is 18921807578203. The reversal of 18921807578063 is 36087570812981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18921807578063 - 2⁶ = 18921807577999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18921807578363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2467145 + ... + 6628002.

It is an arithmetic number, because the mean of its divisors is an integer number (2547182601306).

Almost surely, 2^{18921807578063} is an apocalyptic number.

18921807578063 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18921807578063 is a deficient number, since it is larger than the sum of its proper divisors (1455653232385).

18921807578063 is a wasteful number, since it uses less digits than its factorization.

18921807578063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9255193.

The product of its (nonzero) digits is 40642560, while the sum is 65.

The spelling of 18921807578063 in words is "eighteen trillion, nine hundred twenty-one billion, eight hundred seven million, five hundred seventy-eight thousand, sixty-three".