19878590111 has 2 divisors, whose sum is σ = 19878590112. Its totient is φ = 19878590110.

The previous prime is 19878590107. The next prime is 19878590177. The reversal of 19878590111 is 11109587891.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (11109587891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19878590111 - 2² = 19878590107 is a prime.

It is a super-2 number, since 2×19878590111² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19878590111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19878598111) 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 as a sum of consecutive naturals, namely, 9939295055 + 9939295056.

It is an arithmetic number, because the mean of its divisors is an integer number (9939295056).

Almost surely, 2^19878590111 is an apocalyptic number.

19878590111 is a deficient number, since it is larger than the sum of its proper divisors (1).

19878590111 is an equidigital number, since it uses as much as digits as its factorization.

19878590111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 50.

The spelling of 19878590111 in words is "nineteen billion, eight hundred seventy-eight million, five hundred ninety thousand, one hundred eleven".