13400783865 has 36 divisors (see below), whose sum is σ = 27020360484. Its totient is φ = 6126071616.

The previous prime is 13400783861. The next prime is 13400783909. The reversal of 13400783865 is 56838700431.

It can be written as a sum of positive squares in 2 ways, for example, as 6341255424 + 7059528441 = 79632^2 + 84021^2 .

It is not a de Polignac number, because 13400783865 - 2² = 13400783861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 13400783865.

It is not an unprimeable number, because it can be changed into a prime (13400783861) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3036522 + ... + 3040931.

It is an arithmetic number, because the mean of its divisors is an integer number (750565569).

Almost surely, 2^13400783865 is an apocalyptic number.

13400783865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13400783865 is an abundant number, since it is smaller than the sum of its proper divisors (13619576619).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13400783865 is a wasteful number, since it uses less digits than its factorization.

13400783865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6077478 (or 6077468 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 13400783865 in words is "thirteen billion, four hundred million, seven hundred eighty-three thousand, eight hundred sixty-five".