19994781343 has 4 divisors (see below), whose sum is σ = 20039313600. Its totient is φ = 19950249088.

The previous prime is 19994781283. The next prime is 19994781371. The reversal of 19994781343 is 34318749991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34318749991 = 809 ⋅42421199.

It is a cyclic number.

It is not a de Polignac number, because 19994781343 - 2²¹ = 19992684191 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 (19994781743) 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, 22265455 + ... + 22266352.

It is an arithmetic number, because the mean of its divisors is an integer number (5009828400).

Almost surely, 2^19994781343 is an apocalyptic number.

19994781343 is a deficient number, since it is larger than the sum of its proper divisors (44532257).

19994781343 is an equidigital number, since it uses as much as digits as its factorization.

19994781343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44532256.

The product of its digits is 5878656, while the sum is 58.

The spelling of 19994781343 in words is "nineteen billion, nine hundred ninety-four million, seven hundred eighty-one thousand, three hundred forty-three".