19544878819 has 2 divisors, whose sum is σ = 19544878820. Its totient is φ = 19544878818.

The previous prime is 19544878807. The next prime is 19544878823. The reversal of 19544878819 is 91887844591.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19544878819 - 2¹⁵ = 19544846051 is a prime.

It is a super-2 number, since 2×19544878819² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19544878879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9772439409 + 9772439410.

It is an arithmetic number, because the mean of its divisors is an integer number (9772439410).

Almost surely, 2^19544878819 is an apocalyptic number.

19544878819 is a deficient number, since it is larger than the sum of its proper divisors (1).

19544878819 is an equidigital number, since it uses as much as digits as its factorization.

19544878819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23224320, while the sum is 64.

The spelling of 19544878819 in words is "nineteen billion, five hundred forty-four million, eight hundred seventy-eight thousand, eight hundred nineteen".