1211000019989 has 2 divisors, whose sum is σ = 1211000019990. Its totient is φ = 1211000019988.

The previous prime is 1211000019979. The next prime is 1211000019997. The reversal of 1211000019989 is 9899100001121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1201895616100 + 9104403889 = 1096310^2 + 95417^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211000019989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211000019959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605500009994 + 605500009995.

It is an arithmetic number, because the mean of its divisors is an integer number (605500009995).

Almost surely, 2^{1211000019989} is an apocalyptic number.

It is an amenable number.

1211000019989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211000019989 is an equidigital number, since it uses as much as digits as its factorization.

1211000019989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 41.

The spelling of 1211000019989 in words is "one trillion, two hundred eleven billion, nineteen thousand, nine hundred eighty-nine".