20121011217121 has 2 divisors, whose sum is σ = 20121011217122. Its totient is φ = 20121011217120.

The previous prime is 20121011217089. The next prime is 20121011217133. The reversal of 20121011217121 is 12171211012102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17183420893521 + 2937590323600 = 4145289^2 + 1713940^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121011217121 - 2⁵ = 20121011217089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121011217092 and 20121011217101.

It is not a weakly prime, because it can be changed into another prime (20121011217161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060505608560 + 10060505608561.

It is an arithmetic number, because the mean of its divisors is an integer number (10060505608561).

Almost surely, 2^{20121011217121} is an apocalyptic number.

It is an amenable number.

20121011217121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121011217121 is an equidigital number, since it uses as much as digits as its factorization.

20121011217121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 22.

Adding to 20121011217121 its reverse (12171211012102), we get a palindrome (32292222229223).

The spelling of 20121011217121 in words is "twenty trillion, one hundred twenty-one billion, eleven million, two hundred seventeen thousand, one hundred twenty-one".