13781605 has 8 divisors (see below), whose sum is σ = 16625664. Its totient is φ = 10966800.

The previous prime is 13781591. The next prime is 13781653. The reversal of 13781605 is 50618731.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13781605 - 2⁷ = 13781477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6261 + ... + 8170.

It is an arithmetic number, because the mean of its divisors is an integer number (2078208).

Almost surely, 2^13781605 is an apocalyptic number.

It is an amenable number.

13781605 is a deficient number, since it is larger than the sum of its proper divisors (2844059).

13781605 is a wasteful number, since it uses less digits than its factorization.

13781605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14627.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 13781605 is about 3712.3584148086. The cubic root of 13781605 is about 239.7544073349.

The spelling of 13781605 in words is "thirteen million, seven hundred eighty-one thousand, six hundred five".