20121221201051 has 2 divisors, whose sum is σ = 20121221201052. Its totient is φ = 20121221201050.

The previous prime is 20121221201027. The next prime is 20121221201071. The reversal of 20121221201051 is 15010212212102.

It is an a-pointer prime, because the next prime (20121221201071) can be obtained adding 20121221201051 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20121221201051 - 2³⁴ = 20104041331867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20121221201071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060610600525 + 10060610600526.

It is an arithmetic number, because the mean of its divisors is an integer number (10060610600526).

Almost surely, 2^{20121221201051} is an apocalyptic number.

20121221201051 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121221201051 is an equidigital number, since it uses as much as digits as its factorization.

20121221201051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 20.

Adding to 20121221201051 its reverse (15010212212102), we get a palindrome (35131433413153).

The spelling of 20121221201051 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred one thousand, fifty-one".