13664405 has 8 divisors (see below), whose sum is σ = 16493112. Its totient is φ = 10867648.

The previous prime is 13664389. The next prime is 13664419. The reversal of 13664405 is 50446631.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5410276 + 8254129 = 2326^2 + 2873^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 13664405 - 2⁴ = 13664389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7034 + ... + 8763.

It is an arithmetic number, because the mean of its divisors is an integer number (2061639).

Almost surely, 2^13664405 is an apocalyptic number.

It is an amenable number.

13664405 is a deficient number, since it is larger than the sum of its proper divisors (2828707).

13664405 is a wasteful number, since it uses less digits than its factorization.

13664405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15975.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 13664405 is about 3696.5395980565. The cubic root of 13664405 is about 239.0728406679.

The spelling of 13664405 in words is "thirteen million, six hundred sixty-four thousand, four hundred five".