13405638 has 16 divisors (see below), whose sum is σ = 26875440. Its totient is φ = 4457856.

The previous prime is 13405633. The next prime is 13405657. The reversal of 13405638 is 83650431.

13405638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×13405638² = 359422260374088, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13405631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 298 + ... + 5186.

It is an arithmetic number, because the mean of its divisors is an integer number (1679715).

Almost surely, 2^13405638 is an apocalyptic number.

13405638 is an abundant number, since it is smaller than the sum of its proper divisors (13469802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13405638 is a wasteful number, since it uses less digits than its factorization.

13405638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5351.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 13405638 is about 3661.3710546734. The cubic root of 13405638 is about 237.5540811284.

The spelling of 13405638 in words is "thirteen million, four hundred five thousand, six hundred thirty-eight".