13784638465 has 16 divisors (see below), whose sum is σ = 17927472528. Its totient is φ = 10114580736.

The previous prime is 13784638433. The next prime is 13784638471. The reversal of 13784638465 is 56483648731.

It is a Cunningham number, because it is equal to 117408²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 1 + 13784638464 = 1^2 + 117408^2 .

It is not a de Polignac number, because 13784638465 - 2⁵ = 13784638433 is a prime.

It is a super-2 number, since 2×13784638465² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 665182 + ... + 685591.

It is an arithmetic number, because the mean of its divisors is an integer number (1120467033).

Almost surely, 2^13784638465 is an apocalyptic number.

It is an amenable number.

13784638465 is a deficient number, since it is larger than the sum of its proper divisors (4142834063).

13784638465 is a wasteful number, since it uses less digits than its factorization.

13784638465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1350948.

The product of its digits is 11612160, while the sum is 55.

The spelling of 13784638465 in words is "thirteen billion, seven hundred eighty-four million, six hundred thirty-eight thousand, four hundred sixty-five".