19191387494 has 8 divisors (see below), whose sum is σ = 30302190840. Its totient is φ = 9090657216.

The previous prime is 19191387443. The next prime is 19191387497. The reversal of 19191387494 is 49478319191.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19191387497) 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, 252518219 + ... + 252518294.

It is an arithmetic number, because the mean of its divisors is an integer number (3787773855).

Almost surely, 2^19191387494 is an apocalyptic number.

19191387494 is a deficient number, since it is larger than the sum of its proper divisors (11110803346).

19191387494 is a wasteful number, since it uses less digits than its factorization.

19191387494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505036534.

The product of its digits is 1959552, while the sum is 56.

The spelling of 19191387494 in words is "nineteen billion, one hundred ninety-one million, three hundred eighty-seven thousand, four hundred ninety-four".