100010021 has 2 divisors, whose sum is σ = 100010022. Its totient is φ = 100010020.

The previous prime is 100010017. The next prime is 100010023. The reversal of 100010021 is 120010001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96805921 + 3204100 = 9839^2 + 1790^2 .

It is a cyclic number.

It is not a de Polignac number, because 100010021 - 2² = 100010017 is a prime.

It is a Sophie Germain prime.

Together with 100010023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 100009987 and 100010014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100010023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50005010 + 50005011.

It is an arithmetic number, because the mean of its divisors is an integer number (50005011).

Almost surely, 2^100010021 is an apocalyptic number.

It is an amenable number.

100010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

100010021 is an equidigital number, since it uses as much as digits as its factorization.

100010021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 100010021 is about 10000.5010374481. The cubic root of 100010021 is about 464.1743872973.

Adding to 100010021 its reverse (120010001), we get a palindrome (220020022).

The spelling of 100010021 in words is "one hundred million, ten thousand, twenty-one".