13664215 has 4 divisors (see below), whose sum is σ = 16397064. Its totient is φ = 10931368.

The previous prime is 13664159. The next prime is 13664219. The reversal of 13664215 is 51246631.

13664215 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51246631 = 137 ⋅374063.

It is a cyclic number.

It is not a de Polignac number, because 13664215 - 2⁹ = 13663703 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 (13664219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1366417 + ... + 1366426.

It is an arithmetic number, because the mean of its divisors is an integer number (4099266).

Almost surely, 2^13664215 is an apocalyptic number.

13664215 is a deficient number, since it is larger than the sum of its proper divisors (2732849).

13664215 is an equidigital number, since it uses as much as digits as its factorization.

13664215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2732848.

The product of its digits is 4320, while the sum is 28.

The square root of 13664215 is about 3696.5138982560. The cubic root of 13664215 is about 239.0717325809.

The spelling of 13664215 in words is "thirteen million, six hundred sixty-four thousand, two hundred fifteen".