19891914871 has 8 divisors (see below), whose sum is σ = 20601226800. Its totient is φ = 19184161920.

The previous prime is 19891914869. The next prime is 19891914893. The reversal of 19891914871 is 17841919891.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 19891914871 - 2¹ = 19891914869 is a prime.

It is a super-2 number, since 2×19891914871² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891914271) 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, 363741 + ... + 414838.

It is an arithmetic number, because the mean of its divisors is an integer number (2575153350).

Almost surely, 2^19891914871 is an apocalyptic number.

19891914871 is a deficient number, since it is larger than the sum of its proper divisors (709311929).

19891914871 is an equidigital number, since it uses as much as digits as its factorization.

19891914871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779489.

The product of its digits is 1306368, while the sum is 58.

The spelling of 19891914871 in words is "nineteen billion, eight hundred ninety-one million, nine hundred fourteen thousand, eight hundred seventy-one".