978251997889 has 2 divisors, whose sum is σ = 978251997890. Its totient is φ = 978251997888.

The previous prime is 978251997887. The next prime is 978251997917. The reversal of 978251997889 is 988799152879.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 971673490225 + 6578507664 = 985735^2 + 81108^2 .

It is a cyclic number.

It is not a de Polignac number, because 978251997889 - 2¹ = 978251997887 is a prime.

Together with 978251997887, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (978251997887) 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, 489125998944 + 489125998945.

It is an arithmetic number, because the mean of its divisors is an integer number (489125998945).

Almost surely, 2^978251997889 is an apocalyptic number.

It is an amenable number.

978251997889 is a deficient number, since it is larger than the sum of its proper divisors (1).

978251997889 is an equidigital number, since it uses as much as digits as its factorization.

978251997889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1646023680, while the sum is 82.

The spelling of 978251997889 in words is "nine hundred seventy-eight billion, two hundred fifty-one million, nine hundred ninety-seven thousand, eight hundred eighty-nine".