201021001 has 4 divisors (see below), whose sum is σ = 205695952. Its totient is φ = 196346052.

The previous prime is 201020987. The next prime is 201021043. The reversal of 201021001 is 100120102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201021001 - 2⁷ = 201020873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201021071) 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 in 3 ways as a sum of consecutive naturals, for example, 2337411 + ... + 2337496.

It is an arithmetic number, because the mean of its divisors is an integer number (51423988).

Almost surely, 2^201021001 is an apocalyptic number.

It is an amenable number.

201021001 is a deficient number, since it is larger than the sum of its proper divisors (4674951).

201021001 is an equidigital number, since it uses as much as digits as its factorization.

201021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674950.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 201021001 is about 14178.1875075766. The cubic root of 201021001 is about 585.7970007061.

Adding to 201021001 its reverse (100120102), we get a palindrome (301141103).

It can be divided in two parts, 20102 and 1001, that multiplied together give a palindrome (20122102).

The spelling of 201021001 in words is "two hundred one million, twenty-one thousand, one".