98021981 has 2 divisors, whose sum is σ = 98021982. Its totient is φ = 98021980.

The previous prime is 98021977. The next prime is 98022013. The reversal of 98021981 is 18912089.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56625625 + 41396356 = 7525^2 + 6434^2 .

It is a cyclic number.

It is not a de Polignac number, because 98021981 - 2² = 98021977 is a prime.

It is a super-2 number, since 2×98021981² = 19216617518328722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (98021971) 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, 49010990 + 49010991.

It is an arithmetic number, because the mean of its divisors is an integer number (49010991).

Almost surely, 2^98021981 is an apocalyptic number.

It is an amenable number.

98021981 is a deficient number, since it is larger than the sum of its proper divisors (1).

98021981 is an equidigital number, since it uses as much as digits as its factorization.

98021981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 98021981 is about 9900.6050825189. The cubic root of 98021981 is about 461.0780966971.

The spelling of 98021981 in words is "ninety-eight million, twenty-one thousand, nine hundred eighty-one".