19891125847 has 2 divisors, whose sum is σ = 19891125848. Its totient is φ = 19891125846.

The previous prime is 19891125829. The next prime is 19891125923. The reversal of 19891125847 is 74852119891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19891125847 - 2¹⁹ = 19890601559 is a prime.

It is a super-2 number, since 2×19891125847² (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 (19891129847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9945562923 + 9945562924.

It is an arithmetic number, because the mean of its divisors is an integer number (9945562924).

Almost surely, 2^19891125847 is an apocalyptic number.

19891125847 is a deficient number, since it is larger than the sum of its proper divisors (1).

19891125847 is an equidigital number, since it uses as much as digits as its factorization.

19891125847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 55.

The spelling of 19891125847 in words is "nineteen billion, eight hundred ninety-one million, one hundred twenty-five thousand, eight hundred forty-seven".