13661215 has 4 divisors (see below), whose sum is σ = 16393464. Its totient is φ = 10928968.

The previous prime is 13661201. The next prime is 13661231. The reversal of 13661215 is 51216631.

13661215 is digitally balanced in base 2, 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.

It is a cyclic number.

It is not a de Polignac number, because 13661215 - 2¹⁹ = 13136927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13661215.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1366117 + ... + 1366126.

It is an arithmetic number, because the mean of its divisors is an integer number (4098366).

Almost surely, 2^13661215 is an apocalyptic number.

13661215 is a deficient number, since it is larger than the sum of its proper divisors (2732249).

13661215 is an equidigital number, since it uses as much as digits as its factorization.

13661215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2732248.

The product of its digits is 1080, while the sum is 25.

The square root of 13661215 is about 3696.1080882463. The cubic root of 13661215 is about 239.0542351081.

Adding to 13661215 its reverse (51216631), we get a palindrome (64877846).

It can be divided in two parts, 136 and 61215, that multiplied together give a triangular number (8325240 = T₄₀₈₀).

The spelling of 13661215 in words is "thirteen million, six hundred sixty-one thousand, two hundred fifteen".