2021002001 has 4 divisors (see below), whose sum is σ = 2021428452. Its totient is φ = 2020575552.

The previous prime is 2021001977. The next prime is 2021002031. The reversal of 2021002001 is 1002001202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1002001202 = 2 ⋅501000601.

It can be written as a sum of positive squares in 2 ways, for example, as 1725987025 + 295014976 = 41545^2 + 17176^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021002001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2021002001.

It is not an unprimeable number, because it can be changed into a prime (2021002031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206036 + ... + 215621.

It is an arithmetic number, because the mean of its divisors is an integer number (505357113).

Almost surely, 2^2021002001 is an apocalyptic number.

It is an amenable number.

2021002001 is a deficient number, since it is larger than the sum of its proper divisors (426451).

2021002001 is an equidigital number, since it uses as much as digits as its factorization.

2021002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426450.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 2021002001 is about 44955.5558412973. Note that the first 3 decimals coincide. The cubic root of 2021002001 is about 1264.3158462108.

Adding to 2021002001 its reverse (1002001202), we get a palindrome (3023003203).

It can be divided in two parts, 202 and 1002001, that multiplied together give a palindrome (202404202).

The spelling of 2021002001 in words is "two billion, twenty-one million, two thousand, one".