20121111001 has 2 divisors, whose sum is σ = 20121111002. Its totient is φ = 20121111000.

The previous prime is 20121110987. The next prime is 20121111061. The reversal of 20121111001 is 10011112102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14095625625 + 6025485376 = 118725^2 + 77624^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121111001 - 2²⁷ = 19986893273 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121111061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060555500 + 10060555501.

It is an arithmetic number, because the mean of its divisors is an integer number (10060555501).

Almost surely, 2^20121111001 is an apocalyptic number.

It is an amenable number.

20121111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121111001 is an equidigital number, since it uses as much as digits as its factorization.

20121111001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 20121111001 its reverse (10011112102), we get a palindrome (30132223103).

It can be divided in two parts, 201211 and 11001, that added together give a palindrome (212212).

The spelling of 20121111001 in words is "twenty billion, one hundred twenty-one million, one hundred eleven thousand, one".