13887915409 has 9 divisors (see below), whose sum is σ = 13983671611. Its totient is φ = 13792812880.

The previous prime is 13887915403. The next prime is 13887915421. The reversal of 13887915409 is 90451978831.

It is a happy number.

The square root of 13887915409 is 117847.

It is a perfect power (a square), and thus also a powerful number.

13887915409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 402203025 + 13485712384 = 20055^2 + 116128^2 .

It is a de Polignac number, because none of the positive numbers 2^k-13887915409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13887915409.

It is not an unprimeable number, because it can be changed into a prime (13887915403) 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 in 8 ways as a sum of consecutive naturals, for example, 22508469 + ... + 22509085.

Almost surely, 2^13887915409 is an apocalyptic number.

13887915409 is the 117847-th square number.

13887915409 is the 58924-th centered octagonal number.

It is an amenable number.

13887915409 is a deficient number, since it is larger than the sum of its proper divisors (95756202).

13887915409 is an frugal number, since it uses more digits than its factorization.

13887915409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1616 (or 808 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 55.

It can be divided in two parts, 13887 and 915409, that added together give a square (929296 = 964²).

The spelling of 13887915409 in words is "thirteen billion, eight hundred eighty-seven million, nine hundred fifteen thousand, four hundred nine".