13661550 has 72 divisors (see below), whose sum is σ = 41957136. Its totient is φ = 3121920.

The previous prime is 13661521. The next prime is 13661561. The reversal of 13661550 is 5516631.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 982 + ... + 5318.

It is an arithmetic number, because the mean of its divisors is an integer number (582738).

Almost surely, 2^13661550 is an apocalyptic number.

13661550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13661550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20978568).

13661550 is an abundant number, since it is smaller than the sum of its proper divisors (28295586).

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

13661550 is a wasteful number, since it uses less digits than its factorization.

13661550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4362 (or 4354 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 13661550 is about 3696.1534059073. The cubic root of 13661550 is about 239.0561891196.

It can be divided in two parts, 1366 and 1550, that added together give a square (2916 = 54²).

The spelling of 13661550 in words is "thirteen million, six hundred sixty-one thousand, five hundred fifty".