2001010021 has 4 divisors (see below), whose sum is σ = 2001137632. Its totient is φ = 2000882412.

The previous prime is 2001010009. The next prime is 2001010049. The reversal of 2001010021 is 1200101002.

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 2001010021 - 2⁷ = 2001009893 is a prime.

It is a super-2 number, since 2×2001010021² = 8008082208284840882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001009986 and 2001010013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001010001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36345 + ... + 72958.

It is an arithmetic number, because the mean of its divisors is an integer number (500284408).

Almost surely, 2^2001010021 is an apocalyptic number.

It is an amenable number.

2001010021 is a deficient number, since it is larger than the sum of its proper divisors (127611).

2001010021 is a wasteful number, since it uses less digits than its factorization.

2001010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127610.

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

The square root of 2001010021 is about 44732.6505027368. The cubic root of 2001010021 is about 1260.1331053219.

Adding to 2001010021 its reverse (1200101002), we get a palindrome (3201111023).

The spelling of 2001010021 in words is "two billion, one million, ten thousand, twenty-one".