20805010001 has 4 divisors (see below), whose sum is σ = 21090010212. Its totient is φ = 20520009792.

The previous prime is 20805009977. The next prime is 20805010021. The reversal of 20805010001 is 10001050802.

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 17062629376 + 3742380625 = 130624^2 + 61175^2 .

It is a cyclic number.

It is not a de Polignac number, because 20805010001 - 2³⁰ = 19731268177 is a prime.

It is a super-2 number, since 2×20805010001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20805010021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142499996 + ... + 142500141.

It is an arithmetic number, because the mean of its divisors is an integer number (5272502553).

Almost surely, 2^20805010001 is an apocalyptic number.

It is an amenable number.

20805010001 is a deficient number, since it is larger than the sum of its proper divisors (285000211).

20805010001 is an equidigital number, since it uses as much as digits as its factorization.

20805010001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285000210.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 20805010001 its reverse (10001050802), we get a palindrome (30806060803).

The spelling of 20805010001 in words is "twenty billion, eight hundred five million, ten thousand, one".