13945581 has 32 divisors (see below), whose sum is σ = 22619520. Its totient is φ = 8439552.

The previous prime is 13945573. The next prime is 13945597. The reversal of 13945581 is 18554931.

13945581 is a `hidden beast` number, since 1 + 39 + 45 + 581 = 666.

It is not a de Polignac number, because 13945581 - 2³ = 13945573 is a prime.

It is a super-2 number, since 2×13945581² = 388958458855122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13945531) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23221 + ... + 23813.

It is an arithmetic number, because the mean of its divisors is an integer number (706860).

Almost surely, 2^13945581 is an apocalyptic number.

It is an amenable number.

13945581 is a deficient number, since it is larger than the sum of its proper divisors (8673939).

13945581 is a wasteful number, since it uses less digits than its factorization.

13945581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682 (or 676 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 13945581 is about 3734.3782615049. The cubic root of 13945581 is about 240.7015410857.

The spelling of 13945581 in words is "thirteen million, nine hundred forty-five thousand, five hundred eighty-one".