2001001021 has 8 divisors (see below), whose sum is σ = 2008419840. Its totient is φ = 1993593168.

The previous prime is 2001001019. The next prime is 2001001091. The reversal of 2001001021 is 1201001002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2001001021 - 2¹ = 2001001019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001000995 and 2001001013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001001091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 560775 + ... + 564331.

It is an arithmetic number, because the mean of its divisors is an integer number (251052480).

Almost surely, 2^2001001021 is an apocalyptic number.

It is an amenable number.

2001001021 is a deficient number, since it is larger than the sum of its proper divisors (7418819).

2001001021 is a wasteful number, since it uses less digits than its factorization.

2001001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5483.

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

The square root of 2001001021 is about 44732.5499049629. The cubic root of 2001001021 is about 1260.1312160735.

Adding to 2001001021 its reverse (1201001002), we get a palindrome (3202002023).

The spelling of 2001001021 in words is "two billion, one million, one thousand, twenty-one".