20101001 has 2 divisors, whose sum is σ = 20101002. Its totient is φ = 20101000.

The previous prime is 20100991. The next prime is 20101009. The reversal of 20101001 is 10010102.

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., 12816400 + 7284601 = 3580^2 + 2699^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101001 - 2⁶ = 20100937 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20101009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050500 + 10050501.

It is an arithmetic number, because the mean of its divisors is an integer number (10050501).

Almost surely, 2^20101001 is an apocalyptic number.

It is an amenable number.

20101001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101001 is an equidigital number, since it uses as much as digits as its factorization.

20101001 is an odious number, because the sum of its binary digits is odd.

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

The square root of 20101001 is about 4483.4139893612. The cubic root of 20101001 is about 271.8979261241.

Adding to 20101001 its reverse (10010102), we get a palindrome (30111103).

Multiplying 20101001 by its reverse (10010102), we get a palindrome (201213070312102).

The spelling of 20101001 in words is "twenty million, one hundred one thousand, one".