20111001001001 has 2 divisors, whose sum is σ = 20111001001002. Its totient is φ = 20111001001000.

The previous prime is 20111001000991. The next prime is 20111001001027. The reversal of 20111001001001 is 10010010011102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20106713370601 + 4287630400 = 4484051^2 + 65480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111001001001 is a prime.

It is a super-3 number, since 3×20111001001001³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

20111001001001 is a modest number, since divided by 1001001 gives 20111 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 20111001001001.

It is not a weakly prime, because it can be changed into another prime (20111001001801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055500500500 + 10055500500501.

It is an arithmetic number, because the mean of its divisors is an integer number (10055500500501).

Almost surely, 2^{20111001001001} is an apocalyptic number.

It is an amenable number.

20111001001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111001001001 is an equidigital number, since it uses as much as digits as its factorization.

20111001001001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 20111001001001 its reverse (10010010011102), we get a palindrome (30121011012103).

The spelling of 20111001001001 in words is "twenty trillion, one hundred eleven billion, one million, one thousand, one".