1215385161409 has 4 divisors (see below), whose sum is σ = 1217772952020. Its totient is φ = 1212997370800.

The previous prime is 1215385161401. The next prime is 1215385161433. The reversal of 1215385161409 is 9041615835121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 688853520784 + 526531640625 = 829972^2 + 725625^2 .

It is a cyclic number.

It is not a de Polignac number, because 1215385161409 - 2³ = 1215385161401 is a prime.

It is a super-2 number, since 2×1215385161409² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215385161401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1193894542 + ... + 1193895559.

It is an arithmetic number, because the mean of its divisors is an integer number (304443238005).

Almost surely, 2^{1215385161409} is an apocalyptic number.

It is an amenable number.

1215385161409 is a deficient number, since it is larger than the sum of its proper divisors (2387790611).

1215385161409 is an equidigital number, since it uses as much as digits as its factorization.

1215385161409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2387790610.

The product of its (nonzero) digits is 259200, while the sum is 46.

The spelling of 1215385161409 in words is "one trillion, two hundred fifteen billion, three hundred eighty-five million, one hundred sixty-one thousand, four hundred nine".