19191778413 has 4 divisors (see below), whose sum is σ = 25589037888. Its totient is φ = 12794518940.

The previous prime is 19191778409. The next prime is 19191778421. The reversal of 19191778413 is 31487719191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19191778413 - 2² = 19191778409 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19191778433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3198629733 + ... + 3198629738.

It is an arithmetic number, because the mean of its divisors is an integer number (6397259472).

Almost surely, 2^19191778413 is an apocalyptic number.

It is an amenable number.

19191778413 is a deficient number, since it is larger than the sum of its proper divisors (6397259475).

19191778413 is an equidigital number, since it uses as much as digits as its factorization.

19191778413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6397259474.

The product of its digits is 381024, while the sum is 51.

The spelling of 19191778413 in words is "nineteen billion, one hundred ninety-one million, seven hundred seventy-eight thousand, four hundred thirteen".