13785812569 has 3 divisors (see below), whose sum is σ = 13785929983. Its totient is φ = 13785695156.

The previous prime is 13785812549. The next prime is 13785812587. The reversal of 13785812569 is 96521858731.

The square root of 13785812569 is 117413.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 96521858731 = 379 ⋅254675089.

It can be written as a sum of positive squares in only one way, i.e., 12039575625 + 1746236944 = 109725^2 + 41788^2 .

It is not a de Polignac number, because 13785812569 - 2¹⁹ = 13785288281 is a prime.

It is a super-2 number, since 2×13785812569² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13785812549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 58707 + ... + 176119.

Almost surely, 2^13785812569 is an apocalyptic number.

13785812569 is the 117413-rd square number.

13785812569 is the 58707-th centered octagonal number.

It is an amenable number.

13785812569 is a deficient number, since it is larger than the sum of its proper divisors (117414).

13785812569 is an frugal number, since it uses more digits than its factorization.

13785812569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234826 (or 117413 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 55.

The spelling of 13785812569 in words is "thirteen billion, seven hundred eighty-five million, eight hundred twelve thousand, five hundred sixty-nine".