20001001211001 has 12 divisors (see below), whose sum is σ = 29256035527680. Its totient is φ = 13165215986520.

The previous prime is 20001001210979. The next prime is 20001001211027. The reversal of 20001001211001 is 10011210010002.

It is a happy number.

It is not a de Polignac number, because 20001001211001 - 2⁶ = 20001001210937 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (20001001211101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14065400985 + ... + 14065402406.

It is an arithmetic number, because the mean of its divisors is an integer number (2438002960640).

Almost surely, 2^{20001001211001} is an apocalyptic number.

It is an amenable number.

20001001211001 is a deficient number, since it is larger than the sum of its proper divisors (9255034316679).

20001001211001 is a wasteful number, since it uses less digits than its factorization.

20001001211001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28130803476 (or 28130803473 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20001001211001 its reverse (10011210010002), we get a palindrome (30012211221003).

The spelling of 20001001211001 in words is "twenty trillion, one billion, one million, two hundred eleven thousand, one".