20021100001 has 4 divisors (see below), whose sum is σ = 22881257152. Its totient is φ = 17160942852.

The previous prime is 20021099981. The next prime is 20021100019. The reversal of 20021100001 is 10000112002.

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, and also an emirpimes, since its reverse is a distinct semiprime: 10000112002 = 2 ⋅5000056001.

It is a cyclic number.

It is not a de Polignac number, because 20021100001 - 2³¹ = 17873616353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7), and also a Moran number because the ratio is a prime number: 2860157143 = 20021100001 / (2 + 0 + 0 + 2 + 1 + 1 + 0 + 0 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021100031) 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, 1430078565 + ... + 1430078578.

It is an arithmetic number, because the mean of its divisors is an integer number (5720314288).

Almost surely, 2^20021100001 is an apocalyptic number.

It is an amenable number.

20021100001 is a deficient number, since it is larger than the sum of its proper divisors (2860157151).

20021100001 is an equidigital number, since it uses as much as digits as its factorization.

20021100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2860157150.

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

Adding to 20021100001 its reverse (10000112002), we get a palindrome (30021212003).

The spelling of 20021100001 in words is "twenty billion, twenty-one million, one hundred thousand, one".