20121001001001 has 12 divisors (see below), whose sum is σ = 29069998746880. Its totient is φ = 13411078836120.

The previous prime is 20121001000999. The next prime is 20121001001029. The reversal of 20121001001001 is 10010010012102.

It is a happy number.

It is not a de Polignac number, because 20121001001001 - 2¹ = 20121001000999 is a prime.

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

It is a Duffinian number.

20121001001001 is a modest number, since divided by 1001001 gives 20121 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20121001001501) 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, 243442321 + ... + 243524958.

Almost surely, 2^{20121001001001} is an apocalyptic number.

It is an amenable number.

20121001001001 is a deficient number, since it is larger than the sum of its proper divisors (8948997745879).

20121001001001 is a wasteful number, since it uses less digits than its factorization.

20121001001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486971876 (or 486971873 counting only the distinct ones).

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

Adding to 20121001001001 its reverse (10010010012102), we get a palindrome (30131011013103).

The spelling of 20121001001001 in words is "twenty trillion, one hundred twenty-one billion, one million, one thousand, one".