20001220001 has 32 divisors (see below), whose sum is σ = 24525504000. Its totient is φ = 15921303552.

The previous prime is 20001219983. The next prime is 20001220009. The reversal of 20001220001 is 10002210002.

It is not a de Polignac number, because 20001220001 - 2¹⁸ = 20000957857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20001220009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6024620 + ... + 6027938.

It is an arithmetic number, because the mean of its divisors is an integer number (766422000).

Almost surely, 2^20001220001 is an apocalyptic number.

It is an amenable number.

20001220001 is a deficient number, since it is larger than the sum of its proper divisors (4524283999).

20001220001 is a wasteful number, since it uses less digits than its factorization.

20001220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4001.

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

Adding to 20001220001 its reverse (10002210002), we get a palindrome (30003430003).

Subtracting from 20001220001 its reverse (10002210002), we obtain a palindrome (9999009999).

The spelling of 20001220001 in words is "twenty billion, one million, two hundred twenty thousand, one".