13781408 has 24 divisors (see below), whose sum is σ = 27250020. Its totient is φ = 6860800.

The previous prime is 13781401. The next prime is 13781413. The reversal of 13781408 is 80418731.

It can be written as a sum of positive squares in 2 ways, for example, as 13630864 + 150544 = 3692^2 + 388^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13781401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7808 + ... + 9408.

Almost surely, 2^13781408 is an apocalyptic number.

It is an amenable number.

13781408 is a deficient number, since it is larger than the sum of its proper divisors (13468612).

13781408 is a wasteful number, since it uses less digits than its factorization.

13781408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1880 (or 1872 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 13781408 is about 3712.3318817153. The cubic root of 13781408 is about 239.7532649463.

The spelling of 13781408 in words is "thirteen million, seven hundred eighty-one thousand, four hundred eight".