998188000921 has 2 divisors, whose sum is σ = 998188000922. Its totient is φ = 998188000920.

The previous prime is 998188000819. The next prime is 998188000949. The reversal of 998188000921 is 129000881899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 998160846400 + 27154521 = 999080^2 + 5211^2 .

It is a cyclic number.

It is not a de Polignac number, because 998188000921 - 2¹⁵ = 998187968153 is a prime.

It is not a weakly prime, because it can be changed into another prime (998188003921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499094000460 + 499094000461.

It is an arithmetic number, because the mean of its divisors is an integer number (499094000461).

Almost surely, 2^998188000921 is an apocalyptic number.

It is an amenable number.

998188000921 is a deficient number, since it is larger than the sum of its proper divisors (1).

998188000921 is an equidigital number, since it uses as much as digits as its factorization.

998188000921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 55.

The spelling of 998188000921 in words is "nine hundred ninety-eight billion, one hundred eighty-eight million, nine hundred twenty-one", and thus it is an aban number.