1201211109509 has 2 divisors, whose sum is σ = 1201211109510. Its totient is φ = 1201211109508.

The previous prime is 1201211109467. The next prime is 1201211109559. The reversal of 1201211109509 is 9059011121021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 882575697025 + 318635412484 = 939455^2 + 564478^2 .

It is an emirp because it is prime and its reverse (9059011121021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1201211109509 is a prime.

It is a super-3 number, since 3×1201211109509³ (a number of 37 digits) contains 333 as substring.

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 (1201211109559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600605554754 + 600605554755.

It is an arithmetic number, because the mean of its divisors is an integer number (600605554755).

Almost surely, 2^{1201211109509} is an apocalyptic number.

It is an amenable number.

1201211109509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201211109509 is an equidigital number, since it uses as much as digits as its factorization.

1201211109509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 32.

The spelling of 1201211109509 in words is "one trillion, two hundred one billion, two hundred eleven million, one hundred nine thousand, five hundred nine".