19891914893 has 2 divisors, whose sum is σ = 19891914894. Its totient is φ = 19891914892.

The previous prime is 19891914869. The next prime is 19891914899. The reversal of 19891914893 is 39841919891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15386417764 + 4505497129 = 124042^2 + 67123^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19891914893 is a prime.

It is a super-2 number, since 2×19891914893² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19891914899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9945957446 + 9945957447.

It is an arithmetic number, because the mean of its divisors is an integer number (9945957447).

Almost surely, 2^19891914893 is an apocalyptic number.

It is an amenable number.

19891914893 is a deficient number, since it is larger than the sum of its proper divisors (1).

19891914893 is an equidigital number, since it uses as much as digits as its factorization.

19891914893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5038848, while the sum is 62.

The spelling of 19891914893 in words is "nineteen billion, eight hundred ninety-one million, nine hundred fourteen thousand, eight hundred ninety-three".