998667685889 has 2 divisors, whose sum is σ = 998667685890. Its totient is φ = 998667685888.

The previous prime is 998667685867. The next prime is 998667685891. The reversal of 998667685889 is 988586766899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 885825439489 + 112842246400 = 941183^2 + 335920^2 .

It is a cyclic number.

It is not a de Polignac number, because 998667685889 - 2³² = 994372718593 is a prime.

Together with 998667685891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (998667625889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499333842944 + 499333842945.

It is an arithmetic number, because the mean of its divisors is an integer number (499333842945).

Almost surely, 2^998667685889 is an apocalyptic number.

It is an amenable number.

998667685889 is a deficient number, since it is larger than the sum of its proper divisors (1).

998667685889 is an equidigital number, since it uses as much as digits as its factorization.

998667685889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22574039040, while the sum is 89.

The spelling of 998667685889 in words is "nine hundred ninety-eight billion, six hundred sixty-seven million, six hundred eighty-five thousand, eight hundred eighty-nine".