10021001 has 2 divisors, whose sum is σ = 10021002. Its totient is φ = 10021000.

The previous prime is 10020977. The next prime is 10021003. The reversal of 10021001 is 10012001.

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., 9120400 + 900601 = 3020^2 + 949^2 .

It is an emirp because it is prime and its reverse (10012001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10021001 - 2¹⁸ = 9758857 is a prime.

It is a super-2 number, since 2×10021001² = 200840922084002, which contains 22 as substring.

Together with 10021003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (10021003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5010500 + 5010501.

It is an arithmetic number, because the mean of its divisors is an integer number (5010501).

Almost surely, 2^10021001 is an apocalyptic number.

It is an amenable number.

10021001 is a deficient number, since it is larger than the sum of its proper divisors (1).

10021001 is an equidigital number, since it uses as much as digits as its factorization.

10021001 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 10021001 is about 3165.5964682821. The cubic root of 10021001 is about 215.5941811586.

Adding to 10021001 its reverse (10012001), we get a palindrome (20033002).

Multiplying 10021001 by its reverse (10012001), we get a palindrome (100330272033001).

The spelling of 10021001 in words is "ten million, twenty-one thousand, one".