19939709393 has 4 divisors (see below), whose sum is σ = 19957953588. Its totient is φ = 19921465200.

The previous prime is 19939709381. The next prime is 19939709399. The reversal of 19939709393 is 39390793991.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19798741264 + 140968129 = 140708^2 + 11873^2 .

It is a cyclic number.

It is not a de Polignac number, because 19939709393 - 2⁶ = 19939709329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19939709399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9120458 + ... + 9122643.

It is an arithmetic number, because the mean of its divisors is an integer number (4989488397).

Almost surely, 2^19939709393 is an apocalyptic number.

It is an amenable number.

19939709393 is a deficient number, since it is larger than the sum of its proper divisors (18244195).

19939709393 is a wasteful number, since it uses less digits than its factorization.

19939709393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18244194.

The product of its (nonzero) digits is 11160261, while the sum is 62.

The spelling of 19939709393 in words is "nineteen billion, nine hundred thirty-nine million, seven hundred nine thousand, three hundred ninety-three".