1215125311409 has 2 divisors, whose sum is σ = 1215125311410. Its totient is φ = 1215125311408.

The previous prime is 1215125311373. The next prime is 1215125311471. The reversal of 1215125311409 is 9041135215121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 791115965809 + 424009345600 = 889447^2 + 651160^2 .

It is an emirp because it is prime and its reverse (9041135215121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1215125311409 - 2¹² = 1215125307313 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1215125311709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 607562655704 + 607562655705.

It is an arithmetic number, because the mean of its divisors is an integer number (607562655705).

Almost surely, 2^{1215125311409} is an apocalyptic number.

It is an amenable number.

1215125311409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215125311409 is an equidigital number, since it uses as much as digits as its factorization.

1215125311409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 35.

The spelling of 1215125311409 in words is "one trillion, two hundred fifteen billion, one hundred twenty-five million, three hundred eleven thousand, four hundred nine".