99978101 has 2 divisors, whose sum is σ = 99978102. Its totient is φ = 99978100.

The previous prime is 99978097. The next prime is 99978121. The reversal of 99978101 is 10187999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73702225 + 26275876 = 8585^2 + 5126^2 .

It is an emirp because it is prime and its reverse (10187999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99978101 - 2² = 99978097 is a prime.

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 (99978121) 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, 49989050 + 49989051.

It is an arithmetic number, because the mean of its divisors is an integer number (49989051).

Almost surely, 2^99978101 is an apocalyptic number.

It is an amenable number.

99978101 is a deficient number, since it is larger than the sum of its proper divisors (1).

99978101 is an equidigital number, since it uses as much as digits as its factorization.

99978101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 99978101 is about 9998.9049900477. The cubic root of 99978101 is about 464.1249988364.

The spelling of 99978101 in words is "ninety-nine million, nine hundred seventy-eight thousand, one hundred one".