20021020001 has 4 divisors (see below), whose sum is σ = 20509337604. Its totient is φ = 19532702400.

The previous prime is 20021019989. The next prime is 20021020027. The reversal of 20021020001 is 10002012002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2989464976 + 17031555025 = 54676^2 + 130505^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021020001 - 2¹⁸ = 20020757857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021020051) 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, 244158740 + ... + 244158821.

It is an arithmetic number, because the mean of its divisors is an integer number (5127334401).

Almost surely, 2^20021020001 is an apocalyptic number.

It is an amenable number.

20021020001 is a deficient number, since it is larger than the sum of its proper divisors (488317603).

20021020001 is an equidigital number, since it uses as much as digits as its factorization.

20021020001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488317602.

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

Adding to 20021020001 its reverse (10002012002), we get a palindrome (30023032003).

The spelling of 20021020001 in words is "twenty billion, twenty-one million, twenty thousand, one".