18447271638919 has 4 divisors (see below), whose sum is σ = 18448808027344. Its totient is φ = 18445735250496.

The previous prime is 18447271638893. The next prime is 18447271638953. The reversal of 18447271638919 is 91983617274481.

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

It is a cyclic number.

It is not a de Polignac number, because 18447271638919 - 2²⁷ = 18447137421191 is a prime.

It is a super-2 number, since 2×18447271638919² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18447271638979) 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, 768176202 + ... + 768200215.

It is an arithmetic number, because the mean of its divisors is an integer number (4612202006836).

Almost surely, 2^{18447271638919} is an apocalyptic number.

18447271638919 is a deficient number, since it is larger than the sum of its proper divisors (1536388425).

18447271638919 is a wasteful number, since it uses less digits than its factorization.

18447271638919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1536388424.

The product of its digits is 146313216, while the sum is 70.

The spelling of 18447271638919 in words is "eighteen trillion, four hundred forty-seven billion, two hundred seventy-one million, six hundred thirty-eight thousand, nine hundred nineteen".