19911339887851 has 2 divisors, whose sum is σ = 19911339887852. Its totient is φ = 19911339887850.

The previous prime is 19911339887771. The next prime is 19911339887927. The reversal of 19911339887851 is 15878893311991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19911339887851 - 2¹³ = 19911339879659 is a prime.

It is a super-2 number, since 2×19911339887851² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19911339887251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9955669943925 + 9955669943926.

It is an arithmetic number, because the mean of its divisors is an integer number (9955669943926).

Almost surely, 2^{19911339887851} is an apocalyptic number.

19911339887851 is a deficient number, since it is larger than the sum of its proper divisors (1).

19911339887851 is an equidigital number, since it uses as much as digits as its factorization.

19911339887851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 117573120, while the sum is 73.

The spelling of 19911339887851 in words is "nineteen trillion, nine hundred eleven billion, three hundred thirty-nine million, eight hundred eighty-seven thousand, eight hundred fifty-one".