99941981 has 2 divisors, whose sum is σ = 99941982. Its totient is φ = 99941980.

The previous prime is 99941951. The next prime is 99942023. The reversal of 99941981 is 18914999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85729081 + 14212900 = 9259^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 99941981 - 2¹⁸ = 99679837 is a prime.

It is a super-2 number, since 2×99941981² = 19976799132408722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99941951) 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, 49970990 + 49970991.

It is an arithmetic number, because the mean of its divisors is an integer number (49970991).

Almost surely, 2^99941981 is an apocalyptic number.

It is an amenable number.

99941981 is a deficient number, since it is larger than the sum of its proper divisors (1).

99941981 is an equidigital number, since it uses as much as digits as its factorization.

99941981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 50.

The square root of 99941981 is about 9997.0986291023. The cubic root of 99941981 is about 464.0690992142.

The spelling of 99941981 in words is "ninety-nine million, nine hundred forty-one thousand, nine hundred eighty-one".