20121002189 has 2 divisors, whose sum is σ = 20121002190. Its totient is φ = 20121002188.

The previous prime is 20121002177. The next prime is 20121002201. The reversal of 20121002189 is 98120012102.

It is a balanced prime because it is at equal distance from previous prime (20121002177) and next prime (20121002201).

It can be written as a sum of positive squares in only one way, i.e., 10973610025 + 9147392164 = 104755^2 + 95642^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20121002189 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121002119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060501094 + 10060501095.

It is an arithmetic number, because the mean of its divisors is an integer number (10060501095).

Almost surely, 2^20121002189 is an apocalyptic number.

It is an amenable number.

20121002189 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121002189 is an equidigital number, since it uses as much as digits as its factorization.

20121002189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

The spelling of 20121002189 in words is "twenty billion, one hundred twenty-one million, two thousand, one hundred eighty-nine".