100109921 has 2 divisors, whose sum is σ = 100109922. Its totient is φ = 100109920.

The previous prime is 100109899. The next prime is 100109927. The reversal of 100109921 is 129901001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95335696 + 4774225 = 9764^2 + 2185^2 .

It is an emirp because it is prime and its reverse (129901001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100109921 - 2⁶ = 100109857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (100109927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50054960 + 50054961.

It is an arithmetic number, because the mean of its divisors is an integer number (50054961).

Almost surely, 2^100109921 is an apocalyptic number.

It is an amenable number.

100109921 is a deficient number, since it is larger than the sum of its proper divisors (1).

100109921 is an equidigital number, since it uses as much as digits as its factorization.

100109921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 100109921 is about 10005.4945405012. The cubic root of 100109921 is about 464.3288904474.

The spelling of 100109921 in words is "one hundred million, one hundred nine thousand, nine hundred twenty-one".