13780905 has 16 divisors (see below), whose sum is σ = 22317120. Its totient is φ = 7260608.

The previous prime is 13780903. The next prime is 13780919. The reversal of 13780905 is 50908731.

13780905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 13780905 - 2¹ = 13780903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13780903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4290 + ... + 6779.

It is an arithmetic number, because the mean of its divisors is an integer number (1394820).

Almost surely, 2^13780905 is an apocalyptic number.

13780905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13780905 is a deficient number, since it is larger than the sum of its proper divisors (8536215).

13780905 is a wasteful number, since it uses less digits than its factorization.

13780905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11160.

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 13780905 is about 3712.2641339215. The cubic root of 13780905 is about 239.7503480368.

The spelling of 13780905 in words is "thirteen million, seven hundred eighty thousand, nine hundred five".