13945509 has 6 divisors (see below), whose sum is σ = 20143526. Its totient is φ = 9297000.

The previous prime is 13945493. The next prime is 13945531. The reversal of 13945509 is 90554931.

13945509 is a `hidden beast` number, since 13 + 94 + 550 + 9 = 666.

13945509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 9548100 + 4397409 = 3090^2 + 2097^2 .

It is not a de Polignac number, because 13945509 - 2⁴ = 13945493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13945709) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 774742 + ... + 774759.

Almost surely, 2^13945509 is an apocalyptic number.

It is an amenable number.

13945509 is a deficient number, since it is larger than the sum of its proper divisors (6198017).

13945509 is a wasteful number, since it uses less digits than its factorization.

13945509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1549507 (or 1549504 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 13945509 is about 3734.3686213335. The cubic root of 13945509 is about 240.7011268436.

It can be divided in two parts, 1394 and 5509, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 13945509 in words is "thirteen million, nine hundred forty-five thousand, five hundred nine".