13781856465 has 48 divisors (see below), whose sum is σ = 26556042240. Its totient is φ = 6566037120.

The previous prime is 13781856449. The next prime is 13781856467. The reversal of 13781856465 is 56465818731.

It is a happy number.

13781856465 is a `hidden beast` number, since 1 + 3 + 7 + 8 + 18 + 564 + 65 = 666.

It is not a de Polignac number, because 13781856465 - 2⁴ = 13781856449 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13781856467) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361845 + ... + 398114.

It is an arithmetic number, because the mean of its divisors is an integer number (553250880).

Almost surely, 2^13781856465 is an apocalyptic number.

13781856465 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13781856465 is a deficient number, since it is larger than the sum of its proper divisors (12774185775).

13781856465 is a wasteful number, since it uses less digits than its factorization.

13781856465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760014 (or 760011 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 54.

The spelling of 13781856465 in words is "thirteen billion, seven hundred eighty-one million, eight hundred fifty-six thousand, four hundred sixty-five".