19911339887905 has 8 divisors (see below), whose sum is σ = 24040194417792. Its totient is φ = 15831347542128.

The previous prime is 19911339887851. The next prime is 19911339887927. The reversal of 19911339887905 is 50978893311991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19911339887905 is a prime.

It is a super-2 number, since 2×19911339887905² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12215545129 + ... + 12215546758.

It is an arithmetic number, because the mean of its divisors is an integer number (3005024302224).

Almost surely, 2^{19911339887905} is an apocalyptic number.

It is an amenable number.

19911339887905 is a deficient number, since it is larger than the sum of its proper divisors (4128854529887).

19911339887905 is a wasteful number, since it uses less digits than its factorization.

19911339887905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24431092055.

The product of its (nonzero) digits is 132269760, while the sum is 73.

The spelling of 19911339887905 in words is "nineteen trillion, nine hundred eleven billion, three hundred thirty-nine million, eight hundred eighty-seven thousand, nine hundred five".