19891503049 has 4 divisors (see below), whose sum is σ = 21699821520. Its totient is φ = 18083184580.

The previous prime is 19891503041. The next prime is 19891503053. The reversal of 19891503049 is 94030519891.

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 19891503049 - 2³ = 19891503041 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19891502993 and 19891503011.

It is not an unprimeable number, because it can be changed into a prime (19891503041) 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, 904159219 + ... + 904159240.

It is an arithmetic number, because the mean of its divisors is an integer number (5424955380).

Almost surely, 2^19891503049 is an apocalyptic number.

It is an amenable number.

19891503049 is a deficient number, since it is larger than the sum of its proper divisors (1808318471).

19891503049 is a wasteful number, since it uses less digits than its factorization.

19891503049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1808318470.

The product of its (nonzero) digits is 349920, while the sum is 49.

The spelling of 19891503049 in words is "nineteen billion, eight hundred ninety-one million, five hundred three thousand, forty-nine".