19728771548431 has 4 divisors (see below), whose sum is σ = 21522296234664. Its totient is φ = 17935246862200.

The previous prime is 19728771548407. The next prime is 19728771548501. The reversal of 19728771548431 is 13484517782791.

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 19728771548431 - 2⁵ = 19728771548399 is a prime.

It is a super-2 number, since 2×19728771548431² (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 (19728771548131) 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, 896762343100 + ... + 896762343121.

It is an arithmetic number, because the mean of its divisors is an integer number (5380574058666).

Almost surely, 2^{19728771548431} is an apocalyptic number.

19728771548431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19728771548431 is a deficient number, since it is larger than the sum of its proper divisors (1793524686233).

19728771548431 is a wasteful number, since it uses less digits than its factorization.

19728771548431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1793524686232.

The product of its digits is 94832640, while the sum is 67.

It can be divided in two parts, 19728771 and 548431, that added together give a palindrome (20277202).

The spelling of 19728771548431 in words is "nineteen trillion, seven hundred twenty-eight billion, seven hundred seventy-one million, five hundred forty-eight thousand, four hundred thirty-one".