20121100111001 has 2 divisors, whose sum is σ = 20121100111002. Its totient is φ = 20121100111000.

The previous prime is 20121100110983. The next prime is 20121100111037. The reversal of 20121100111001 is 10011100112102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19017972121600 + 1103127989401 = 4360960^2 + 1050299^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121100111001 - 2¹⁰ = 20121100109977 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121100111051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060550055500 + 10060550055501.

It is an arithmetic number, because the mean of its divisors is an integer number (10060550055501).

Almost surely, 2^{20121100111001} is an apocalyptic number.

It is an amenable number.

20121100111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121100111001 is an equidigital number, since it uses as much as digits as its factorization.

20121100111001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 20121100111001 its reverse (10011100112102), we get a palindrome (30132200223103).

The spelling of 20121100111001 in words is "twenty trillion, one hundred twenty-one billion, one hundred million, one hundred eleven thousand, one".