20120212121981 has 2 divisors, whose sum is σ = 20120212121982. Its totient is φ = 20120212121980.

The previous prime is 20120212121951. The next prime is 20120212122011. The reversal of 20120212121981 is 18912121202102.

It is a balanced prime because it is at equal distance from previous prime (20120212121951) and next prime (20120212122011).

It can be written as a sum of positive squares in only one way, i.e., 20099611261081 + 20600860900 = 4483259^2 + 143530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20120212121981 is a prime.

It is a super-2 number, since 2×20120212121981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20120212121951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060106060990 + 10060106060991.

It is an arithmetic number, because the mean of its divisors is an integer number (10060106060991).

Almost surely, 2^{20120212121981} is an apocalyptic number.

It is an amenable number.

20120212121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20120212121981 is an equidigital number, since it uses as much as digits as its factorization.

20120212121981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 32.

The spelling of 20120212121981 in words is "twenty trillion, one hundred twenty billion, two hundred twelve million, one hundred twenty-one thousand, nine hundred eighty-one".