19012991123 has 8 divisors (see below), whose sum is σ = 22172584800. Its totient is φ = 16296849240.

The previous prime is 19012991113. The next prime is 19012991161. The reversal of 19012991123 is 32119921091.

It is not a de Polignac number, because 19012991123 - 2¹⁸ = 19012728979 is a prime.

It is a super-2 number, since 2×19012991123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19012991113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27715388 + ... + 27716073.

It is an arithmetic number, because the mean of its divisors is an integer number (2771573100).

Almost surely, 2^19012991123 is an apocalyptic number.

19012991123 is a deficient number, since it is larger than the sum of its proper divisors (3159593677).

19012991123 is an frugal number, since it uses more digits than its factorization.

19012991123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55431482 (or 55431468 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 38.

The spelling of 19012991123 in words is "nineteen billion, twelve million, nine hundred ninety-one thousand, one hundred twenty-three".