19797810643 has 36 divisors (see below), whose sum is σ = 22671294912. Its totient is φ = 17168124960.

The previous prime is 19797810629. The next prime is 19797810647. The reversal of 19797810643 is 34601879791.

It is not a de Polignac number, because 19797810643 - 2²¹ = 19795713491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19797810647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 121458880 + ... + 121459042.

It is an arithmetic number, because the mean of its divisors is an integer number (629758192).

Almost surely, 2^19797810643 is an apocalyptic number.

19797810643 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

19797810643 is a deficient number, since it is larger than the sum of its proper divisors (2873484269).

19797810643 is an equidigital number, since it uses as much as digits as its factorization.

19797810643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 55.

The spelling of 19797810643 in words is "nineteen billion, seven hundred ninety-seven million, eight hundred ten thousand, six hundred forty-three".